backend: stop calling wl_display_terminate()

Leave it up to the compositor to decide what to do when a backend
becomes unavailable.

backend/drm/drm.c

@@ -1790,7 +1790,7 @@ int handle_drm_event(int fd, uint32_t mask, void *data) {
 
 	if (drmHandleEvent(fd, &event) != 0) {
 		wlr_log(WLR_ERROR, "drmHandleEvent failed");
-		wl_display_terminate(drm->display);
+		wlr_backend_destroy(&drm->backend);
 	}
 	return 1;
 }

backend/libinput/backend.c

@@ -51,7 +51,7 @@ static int handle_libinput_readable(int fd, uint32_t mask, void *_backend) {
 	int ret = libinput_dispatch(backend->libinput_context);
 	if (ret != 0) {
 		wlr_log(WLR_ERROR, "Failed to dispatch libinput: %s", strerror(-ret));
-		wl_display_terminate(backend->display);
+		wlr_backend_destroy(&backend->backend);
 		return 0;
 	}
 	struct libinput_event *event;

backend/wayland/backend.c

@@ -59,7 +59,7 @@ static int dispatch_events(int fd, uint32_t mask, void *data) {
 		if (mask & WL_EVENT_ERROR) {
 			wlr_log(WLR_ERROR, "Failed to read from remote Wayland display");
 		}
-		wl_display_terminate(wl->local_display);
+		wlr_backend_destroy(&wl->backend);
 		return 0;
 	}
 
@@ -77,7 +77,7 @@ static int dispatch_events(int fd, uint32_t mask, void *data) {
 
 	if (count < 0) {
 		wlr_log(WLR_ERROR, "Failed to dispatch remote Wayland display");
-		wl_display_terminate(wl->local_display);
+		wlr_backend_destroy(&wl->backend);
 		return 0;
 	}
 	return count;

backend/x11/backend.c

@@ -132,7 +132,7 @@ static int x11_event(int fd, uint32_t mask, void *data) {
 		if (mask & WL_EVENT_ERROR) {
 			wlr_log(WLR_ERROR, "Failed to read from X11 server");
 		}
-		wl_display_terminate(x11->wl_display);
+		wlr_backend_destroy(&x11->backend);
 		return 0;
 	}
 
@@ -145,7 +145,7 @@ static int x11_event(int fd, uint32_t mask, void *data) {
 	int ret = xcb_connection_has_error(x11->xcb);
 	if (ret != 0) {
 		wlr_log(WLR_ERROR, "X11 connection error (%d)", ret);
-		wl_display_terminate(x11->wl_display);
+		wlr_backend_destroy(&x11->backend);
 	}
 
 	return 0;