backend: revert bad memory leak fix

This essentially reverts the commit mentioned in the fixes line, as it
causes crashes with using a trigger timeout + command.

Fixes: 807473c ("fixed memory leak detected by ASAN")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

backend.c

@@ -2451,10 +2451,8 @@ static void run_threads(struct sk_out *sk_out)
 							strerror(ret));
 			} else {
 				pid_t pid;
-				struct fio_file **files;
 				void *eo;
 				dprint(FD_PROCESS, "will fork\n");
-				files = td->files;
 				eo = td->eo;
 				read_barrier();
 				pid = fork();
@@ -2465,9 +2463,6 @@ static void run_threads(struct sk_out *sk_out)
 					_exit(ret);
 				} else if (i == fio_debug_jobno)
 					*fio_debug_jobp = pid;
-				// freeing previously allocated memory for files
-				// this memory freed MUST NOT be shared between processes, only the pointer itself may be shared within TD
-				free(files);
 				free(eo);
 				free(fd);
 				fd = NULL;