ext4: remove unnecessary error check

Remove unnecessary error check in ext4_file_write_iter(),
because this check will be done in upcoming later function --
ext4_write_checks() -> generic_write_checks()

Change-Id: I7b0ab27f693a50765c15b5eaa3f4e7c38f42e01e
Signed-off-by: shisiyuan <shisiyuan@xiaomi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/file.c

@@ -230,8 +230,6 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (IS_DAX(inode))
 		return ext4_dax_write_iter(iocb, from);
 #endif
-	if (!o_direct && (iocb->ki_flags & IOCB_NOWAIT))
-		return -EOPNOTSUPP;
 
 	if (!inode_trylock(inode)) {
 		if (iocb->ki_flags & IOCB_NOWAIT)