s3: smbd: Currently if getwd() fails after a chdir(), we panic.
Change this to return to the previous $cwd, and return -1 for the chdir().
If the return to the previous $cwd fails, still panic as we
can't return an unknown state.
Also do early return from failing SMB_VFS_CHDIR, reducing indentation level
BUG: https://bugzilla.samba.org/show_bug.cgi?id=13027
Signed-off-by: Jeremy Allison <jra@samba.org>
Signed-off-by: Ralph Böhme <slow@samba.org>
(cherry picked from commit
272f1c9febdf51dd6ec7b862d33d2010621e840a)