UBIFS: constify operations

Mark super, file, and inode operation structcutes with 'const'.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index bf373745..17443d9 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1541,7 +1541,7 @@
 	return 0;
 }
 
-struct address_space_operations ubifs_file_address_operations = {
+const struct address_space_operations ubifs_file_address_operations = {
 	.readpage       = ubifs_readpage,
 	.writepage      = ubifs_writepage,
 	.write_begin    = ubifs_write_begin,
@@ -1551,7 +1551,7 @@
 	.releasepage    = ubifs_releasepage,
 };
 
-struct inode_operations ubifs_file_inode_operations = {
+const struct inode_operations ubifs_file_inode_operations = {
 	.setattr     = ubifs_setattr,
 	.getattr     = ubifs_getattr,
 #ifdef CONFIG_UBIFS_FS_XATTR
@@ -1562,14 +1562,14 @@
 #endif
 };
 
-struct inode_operations ubifs_symlink_inode_operations = {
+const struct inode_operations ubifs_symlink_inode_operations = {
 	.readlink    = generic_readlink,
 	.follow_link = ubifs_follow_link,
 	.setattr     = ubifs_setattr,
 	.getattr     = ubifs_getattr,
 };
 
-struct file_operations ubifs_file_operations = {
+const struct file_operations ubifs_file_operations = {
 	.llseek         = generic_file_llseek,
 	.read           = do_sync_read,
 	.write          = do_sync_write,