Update rustfmt submodule

[Amanieu]

The version of rustfmt currently shipped with nightly breaks code that uses break 'label. This PR updates the submodule to include the fix (rust-lang/rustfmt#2774).

[rust-highfive]

r? @alexcrichton

(rust_highfive has picked a reviewer for you, use r? to override)

[rust-highfive]

Warning

• These commits modify submodules.

[Mark-Simulacrum]

r=me pending travis @bors delegate+

[bors]

✌️ @Amanieu can now approve this pull request

[rust-highfive]

The job x86_64-gnu-llvm-3.9 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

######################################################################## 100.0%
[00:01:08] extracting /checkout/obj/build/cache/2018-05-10/cargo-beta-x86_64-unknown-linux-gnu.tar.gz
[00:01:08]     Updating registry `https://github.com/rust-lang/crates.io-index`
[00:01:28]     Updating git repository `https://github.com/rust-lang-nursery/rustfmt`
[00:01:30] error: the lock file needs to be updated but --locked was passed to prevent this
[00:01:30] failed to run: /checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo build --manifest-path /checkout/src/bootstrap/Cargo.toml --locked
[00:01:30] make: *** [prepare] Error 1
[00:01:30] make: *** [prepare] Error 1
[00:01:30] Makefile:81: recipe for target 'prepare' failed
[00:01:31]     Updating registry `https://github.com/rust-lang/crates.io-index`
[00:01:31]     Updating registry `https://github.com/rust-lang/crates.io-index`
[00:01:31] error: the lock file needs to be updated but --locked was passed to prevent this
[00:01:31] failed to run: /checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo build --manifest-path /checkout/src/bootstrap/Cargo.toml --locked
[00:01:31] make: *** [prepare] Error 1
[00:01:31] make: *** [prepare] Error 1
[00:01:31] Makefile:81: recipe for target 'prepare' failed
[00:01:33]     Updating registry `https://github.com/rust-lang/crates.io-index`
[00:01:33]     Updating registry `https://github.com/rust-lang/crates.io-index`
[00:01:34] error: the lock file needs to be updated but --locked was passed to prevent this
[00:01:34] failed to run: /checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo build --manifest-path /checkout/src/bootstrap/Cargo.toml --locked
[00:01:34] make: *** [prepare] Error 1
[00:01:34] make: *** [prepare] Error 1
[00:01:34] Makefile:81: recipe for target 'prepare' failed
[00:01:37]     Updating registry `https://github.com/rust-lang/crates.io-index`
[00:01:37]     Updating registry `https://github.com/rust-lang/crates.io-index`
[00:01:37] error: the lock file needs to be updated but --locked was passed to prevent this
[00:01:37] failed to run: /checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo build --manifest-path /checkout/src/bootstrap/Cargo.toml --locked
[00:01:37] make: *** [prepare] Error 1
[00:01:37] make: *** [prepare] Error 1
[00:01:37] Makefile:81: recipe for target 'prepare' failed
[00:01:41]     Updating registry `https://github.com/rust-lang/crates.io-index`
[00:01:41]     Updating registry `https://github.com/rust-lang/crates.io-index`
[00:01:42] error: the lock file needs to be updated but --locked was passed to prevent this
[00:01:42] failed to run: /checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo build --manifest-path /checkout/src/bootstrap/Cargo.toml --locked
[00:01:42] make: *** [prepare] Error 1
[00:01:42] make: *** [prepare] Error 1
[00:01:42] Makefile:81: recipe for target 'prepare' failed
[00:01:42] The command has failed after 5 attempts.

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[kennytm]

cc #51677

[kennytm]

@bors r=Mark-Simulacrum p=4

[bors]

📌 Commit c44be4c has been approved by Mark-Simulacrum

[bors]

⌛ Testing commit c44be4c with merge 8fb1180...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: Mark-Simulacrum
Pushing 8fb1180 to master...