io_uring: kill io_rw_buffer_select() wrapper

After the recent changes, this is direct call to io_buffer_select()
anyway. With this change, there are no wrappers left for provided
buffer selection.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -3486,12 +3486,6 @@ static void __user *io_buffer_select(struct io_kiocb *req, size_t *len,
 	return ERR_PTR(-ENOBUFS);
 }
 
-static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
-					unsigned int issue_flags)
-{
-	return io_buffer_select(req, len, req->buf_index, issue_flags);
-}
-
 #ifdef CONFIG_COMPAT
 static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
 				unsigned int issue_flags)
@@ -3499,7 +3493,7 @@ static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
 	struct compat_iovec __user *uiov;
 	compat_ssize_t clen;
 	void __user *buf;
-	ssize_t len;
+	size_t len;
 
 	uiov = u64_to_user_ptr(req->rw.addr);
 	if (!access_ok(uiov, sizeof(*uiov)))
@@ -3510,7 +3504,7 @@ static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
 		return -EINVAL;
 
 	len = clen;
-	buf = io_rw_buffer_select(req, &len, issue_flags);
+	buf = io_buffer_select(req, &len, req->buf_index, issue_flags);
 	if (IS_ERR(buf))
 		return PTR_ERR(buf);
 	iov[0].iov_base = buf;
@@ -3532,7 +3526,7 @@ static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
 	len = iov[0].iov_len;
 	if (len < 0)
 		return -EINVAL;
-	buf = io_rw_buffer_select(req, &len, issue_flags);
+	buf = io_buffer_select(req, &len, req->buf_index, issue_flags);
 	if (IS_ERR(buf))
 		return PTR_ERR(buf);
 	iov[0].iov_base = buf;
@@ -3588,7 +3582,8 @@ static struct iovec *__io_import_iovec(int rw, struct io_kiocb *req,
 
 	if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
 		if (req->flags & REQ_F_BUFFER_SELECT) {
-			buf = io_rw_buffer_select(req, &sqe_len, issue_flags);
+			buf = io_buffer_select(req, &sqe_len, req->buf_index,
+						issue_flags);
 			if (IS_ERR(buf))
 				return ERR_CAST(buf);
 			req->rw.len = sqe_len;