ext4: switch EXT4_IOC_RESIZE_FS to mnt_want_write_file()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index e34deac..23788b3 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -390,7 +390,7 @@
 		if (err)
 			return err;
 
-		err = mnt_want_write(filp->f_path.mnt);
+		err = mnt_want_write_file(filp);
 		if (err)
 			goto resizefs_out;
 
@@ -402,7 +402,7 @@
 		}
 		if (err == 0)
 			err = err2;
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 resizefs_out:
 		ext4_resize_end(sb);
 		return err;