generic_acl_set 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, vfs must update it.
Port of ext3 patch by Miao Xie <miaox@cn.fujitsu.com>.
CC: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
                        if (error < 0)
                                goto failed;
                        inode->i_mode = mode;
+                       inode->i_ctime = CURRENT_TIME;
                        if (error == 0) {
                                posix_acl_release(acl);
                                acl = NULL;