doc: make openssl maintenance position independent

It used to have some `cd` commands that if done literally would
invalidate the subsequent commands. Modify them to be more accurate,
which also simplifies pasting them directly into the console from the
guide while doing an update.

PR-URL: #32977
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>

doc/guides/maintaining-openssl.md

@@ -57,7 +57,7 @@ This updates all sources in deps/openssl/openssl by:
 Use `make` to regenerate all platform dependent files in
 `deps/openssl/config/archs/`:
 ```sh
-% cd deps/openssl/config; make
+% make -C deps/openssl/config
 ```
 
 ## 3. Check diffs
@@ -66,8 +66,7 @@ Check diffs if updates are right. Even if no updates in openssl
 sources, `buildinf.h` files will be updated for they have a timestamp
 data in them.
 ```sh
-% cd deps/openssl/config
-% git diff
+% git diff -- deps/openssl
 ```
 
 *Note*: On Windows, OpenSSL Configure generates `makefile` that can be
@@ -95,8 +94,7 @@ The commit message can be (with the openssl version set to the relevant value):
 
  After an OpenSSL source update, all the config files need to be
  regenerated and committed by:
-    $ cd deps/openssl/config
-    $ make
+    $ make -C deps/openssl/config
     $ git add deps/openssl/config/archs
     $ git add deps/openssl/openssl/include/crypto/bn_conf.h
     $ git add deps/openssl/openssl/include/crypto/dso_conf.h