docs: Improve man mount.cifs.
Add hint about specifying the workgroup in the credentials file.
Whitespace cleanup.
This fixes bug #4541.
Patch based on proposed patch from Christian Perrier <bubulle@debian.org>.
Thanks for reporting and providing a patch!
Karolin
(cherry picked from commit
1f7e09ea542df3a2f5f553c0cb11a39c74712950)
(cherry picked from commit
b99d98ff2ef5491979301656e7f516d3c8829f6e)
(cherry picked from commit
1900233ede3083410eb3dc691d2d486c5340ccc4)
(cherry picked from commit
47f4662b6d727f2901d630d74792a6a971b54662)