fsr: more tidy up work

fsr: more tidy up work

Make the mountpoint stat structure "ms" local to
find_mountpoint_check(), no caller uses it.  And remove 3rd "sb2"
statbuf in that same function, we can just re-use ms.

rename "struct mntent *mp" to "struct mntent *mnt" - "mp" has its
own common meaning in xfsprogs.

And a couple more minor whitespace removals.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>