io_uring: wire up allocated direct descriptors for socket

The socket support was merged in an earlier branch that didn't yet
have support for allocating direct descriptors, hence only open
and accept got support for that.

Do the one-liner to enable it now, so we have consistent support for
any request that can instantiate a file/direct descriptor.
Reviewed-by: NHao Xu <howeyxu@tencent.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -6676,8 +6676,8 @@ static int io_socket(struct io_kiocb *req, unsigned int issue_flags)
 		fd_install(fd, file);
 		ret = fd;
 	} else {
-		ret = io_install_fixed_file(req, file, issue_flags,
-					    sock->file_slot - 1);
+		ret = io_fixed_fd_install(req, issue_flags, file,
+					    sock->file_slot);
 	}
 	__io_req_complete(req, issue_flags, ret, 0);
 	return 0;