ext2: update ctime when changing the file's permission by setfacl

ext2 didn't update the ctime of the file when its permission was changed.

Steps to reproduce:
 # touch aaa
 # stat -c %Z aaa
 1275289822
 # setfacl -m  'u::x,g::x,o::x' aaa
 # stat -c %Z aaa
 1275289822                         <- unchanged

But, according to the spec of the ctime, ext2 must update it.

Port of ext3 patch by Miao Xie <miaox@cn.fujitsu.com>.
Signed-off-by: Jan Kara <jack@suse.cz>

fs/ext2/acl.c

@@ -200,6 +200,7 @@ ext2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
 					return error;
 				else {
 					inode->i_mode = mode;
+					inode->i_ctime = CURRENT_TIME_SEC;
 					mark_inode_dirty(inode);
 					if (error == 0)
 						acl = NULL;