cygwin: fix member types of statfs

[Berrysoft]

Description

This is a fix for #4321 . The member types of statfs should be c_long instead of c_ulong.

Sources

https://github.com/cygwin/cygwin/blob/bc026427bd5408999e73ff61ca2b91a343176864/winsup/cygwin/include/sys/vfs.h

Checklist

• Relevant tests in libc-test/semver have been updated
• No placeholder or unstable values like *LAST or *MAX are
  included (see #3131)
• Tested locally (cd libc-test && cargo test --target mytarget);
  especially relevant for platforms that may not be checked in CI

[rustbot]

r? @tgross35

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