[GFS2] More code style updates

As per Jan Engelhardt's fifth email. This has most of the changes
recommended, which is the removal of casts which are not required,
some indenting fixes and similar.

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index c680f05..2f38313 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -1014,7 +1014,7 @@
 
 /**
  * gfs2_getattr - Read out an inode's attributes
- * @mnt: ?
+ * @mnt: The vfsmount the inode is being accessed from
  * @dentry: The dentry to stat
  * @stat: The inode's stats
  *