fs/direct-io.c: remove some left over checks

We know that "ret > 0" is true here.  These tests were left over from
commit 02afc27f ('direct-io: Handle O_(D)SYNC AIO') and aren't
needed any more.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/block_dev.c

@@ -1523,7 +1523,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		ssize_t err;
 
 		err = generic_write_sync(file, pos, ret);
-		if (err < 0 && ret > 0)
+		if (err < 0)
 			ret = err;
 	}
 	blk_finish_plug(&plug);

fs/btrfs/file.c

@@ -1797,7 +1797,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
 	BTRFS_I(inode)->last_sub_trans = root->log_transid;
 	if (num_written > 0) {
 		err = generic_write_sync(file, pos, num_written);
-		if (err < 0 && num_written > 0)
+		if (err < 0)
 			num_written = err;
 	}
 

fs/ext4/file.c

@@ -153,7 +153,7 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
 		ssize_t err;
 
 		err = generic_write_sync(file, iocb->ki_pos - ret, ret);
-		if (err < 0 && ret > 0)
+		if (err < 0)
 			ret = err;
 	}
 	blk_finish_plug(&plug);