[GFS2] Mark file_operations const

As per Arjan's patches:
http://www.kernel.org/git/?p=linux/kernel/git/steve/gfs2-2.6.git;a=commitdiff;h=99ac48f54a91d02140c497edc31dc57d4bc5c85d
and
http://www.kernel.org/git/?p=linux/kernel/git/steve/gfs2-2.6.git;a=commitdiff;h=4b6f5d20b04dcbc3d888555522b90ba6d36c4106

make the GFS2 file_operations structures const.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/ops_file.c

@@ -950,7 +950,7 @@ static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
 		return do_flock(file, cmd, fl);
 }
 
-struct file_operations gfs2_file_fops = {
+const struct file_operations gfs2_file_fops = {
 	.llseek = gfs2_llseek,
 	.read = gfs2_read,
 	.readv = gfs2_file_readv,
@@ -970,7 +970,7 @@ struct file_operations gfs2_file_fops = {
 	.splice_write = generic_file_splice_write,
 };
 
-struct file_operations gfs2_dir_fops = {
+const struct file_operations gfs2_dir_fops = {
 	.readdir = gfs2_readdir,
 	.unlocked_ioctl = gfs2_ioctl,
 	.open = gfs2_open,

fs/gfs2/ops_file.h

@@ -14,7 +14,7 @@ extern int gfs2_internal_read(struct gfs2_inode *ip,
 			      struct file_ra_state *ra_state,
 			      char *buf, loff_t *pos, unsigned size);
 
-extern struct file_operations gfs2_file_fops;
-extern struct file_operations gfs2_dir_fops;
+extern const struct file_operations gfs2_file_fops;
+extern const struct file_operations gfs2_dir_fops;
 
 #endif /* __OPS_FILE_DOT_H__ */