core: Prefer EXIT_FAILURE.

src/task.c

@@ -1101,7 +1101,7 @@ void tf_task_on_receive_packet(int packetType, const char* begin, size_t length,
 		}
 		else
 		{
-			exit(1);
+			exit(EXIT_FAILURE);
 		}
 		break;
 	case kSetImports:
@@ -1699,7 +1699,7 @@ void tf_task_activate(tf_task_t* task)
 				else
 				{
 					tf_printf("Assignment missing '=': %s.\n", assignment);
-					exit(1);
+					exit(EXIT_FAILURE);
 				}
 			}
 			tf_free(copy);