set async ctx to 0

prevent crash in timeout_f not being set but reactor still somehow timing out fds

async.c

@@ -80,6 +80,8 @@ int register_async_fd(int fd, async_resume_fd *f, void *resume_param)
 		return -1;
 	}
 
+	memset(ctx,0,sizeof(async_ctx));
+
 	ctx->resume_f = f;
 	ctx->resume_param = resume_param;
 
@@ -298,6 +300,8 @@ int async_script_launch(struct sip_msg *msg, struct action* a,
 		return -1;
 	}
 
+	memset(ctx,0,sizeof(async_launch_ctx));
+
 	async_status = ASYNC_NO_IO; /*assume defauly status "no IO done" */
 
 	return_code = ((const acmd_export_t*)(a->elem[0].u.data_const))->function(msg,

modules/tm/async.c

@@ -267,6 +267,8 @@ int t_handle_async(struct sip_msg *msg, struct action* a,
 		goto failure;
 	}
 
+	memset(ctx,0,sizeof(async_tm_ctx));
+
 	async_status = ASYNC_NO_IO; /*assume default status "no IO done" */
 	return_code = ((const acmd_export_t*)(a->elem[0].u.data_const))->function(msg,
 			(async_ctx*)ctx,