plugins: Fix -Wsign-compare on Linux

plugins/linux-capture/xshm-input.c

@@ -367,7 +367,7 @@ static bool xshm_server_changed(obs_properties_t *props, obs_property_t *p,
 		if (name == NULL) {
 			int ret = snprintf(name_tmp, sizeof(name_tmp),
 					   "%" PRIuFAST32, i);
-			if (ret >= sizeof(name_tmp))
+			if (ret >= (int)sizeof(name_tmp))
 				blog(LOG_DEBUG,
 				     "linux-capture: A format truncation may have occurred."
 				     " This can be ignored since it is quite improbable.");

plugins/linux-v4l2/v4l2-input.c

@@ -419,7 +419,7 @@ static void v4l2_device_list(obs_property_t *prop, obs_data_t *settings)
 		int ret = snprintf(unique_device_name,
 				   sizeof(unique_device_name), "%s (%s)",
 				   video_cap.card, video_cap.bus_info);
-		if (ret >= sizeof(unique_device_name))
+		if (ret >= (int)sizeof(unique_device_name))
 			blog(LOG_DEBUG,
 			     "linux-v4l2: A format truncation may have occurred."
 			     " This can be ignored since it is quite improbable.");