io_uring: kill extra check in fixed io_file_get()

ctx->nr_user_files == 0 IFF ctx->file_data == NULL and there fixed files
are not used. Hence, verifying fds only against ctx->nr_user_files is
enough. Remove the other check from hot path.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -5987,8 +5987,7 @@ static int io_file_get(struct io_submit_state *state, struct io_kiocb *req,
 	struct file *file;
 
 	if (fixed) {
-		if (unlikely(!ctx->file_data ||
-		    (unsigned) fd >= ctx->nr_user_files))
+		if (unlikely((unsigned int)fd >= ctx->nr_user_files))
 			return -EBADF;
 		fd = array_index_nospec(fd, ctx->nr_user_files);
 		file = io_file_from_index(ctx, fd);