Squash remaining GCC7 -Wimplicit-fallthrough warnings.

content/llcache.c

@@ -2698,9 +2698,7 @@ static void llcache_fetch_callback(const fetch_msg *msg, void *p)
 			error = llcache_object_refetch(object);
 			break;
 		}
-		/* Otherwise fall through to error, setting the message to
-		 * a timeout
-		 */
+		/* Fall through */
 	case FETCH_ERROR:
 		/* An error occurred while fetching */
 		/* The fetch has has already been cleaned up by the fetcher */

frontends/gtk/download.c

@@ -331,6 +331,7 @@ static gboolean nsgtk_download_update(gboolean force_update)
 		switch (dl->status) {
 		case NSGTK_DOWNLOAD_WORKING:
 			pulse_mode = TRUE;
+			/* Fall through */
 
 		case NSGTK_DOWNLOAD_NONE:
 			dl->speed = dl->size_downloaded /
@@ -347,6 +348,7 @@ static gboolean nsgtk_download_update(gboolean force_update)
 
 			nsgtk_downloads_num_active++;
 			update = TRUE;
+			/* Fall through */
 
 		case NSGTK_DOWNLOAD_COMPLETE:
 			downloaded += dl->size_downloaded;

render/html_interaction.c

@@ -697,6 +697,7 @@ void html_mouse_action(struct content *c, struct browser_window *bw,
 				form_radio_set(gadget);
 			break;
 		case GADGET_IMAGE:
+			/* This falls through to SUBMIT */
 			if (mouse & BROWSER_MOUSE_CLICK_1) {
 				struct image_input_coords *coords, *oldcoords;
 				/** \todo Find a way to not ignore errors */