Avoid compile error.

"a label can only be part of a statement and a declaration is not a
statement"

plugins/persist-sqlite/base_msgs.c

@@ -84,27 +84,29 @@ static char *properties_to_json(const mosquitto_property *properties)
 				break;
 
 			case MQTT_PROP_CORRELATION_DATA:
-				/* bin */
-				void *binval = NULL;
-				mosquitto_property_read_binary(properties, propid, &binval, &len, false);
-				char *hexval = malloc(2*(size_t)len + 1);
-				if(!hexval){
+				{
+					/* bin */
+					void *binval = NULL;
+					mosquitto_property_read_binary(properties, propid, &binval, &len, false);
+					char *hexval = malloc(2*(size_t)len + 1);
+					if(!hexval){
+						free(binval);
+						cJSON_Delete(array);
+						return NULL;
+					}
+					for(int i=0; i<len; i++){
+						sprintf(&hexval[i*2], "%02X", ((uint8_t *)binval)[i]);
+					}
+					hexval[2*len] = '\0';
 					free(binval);
-					cJSON_Delete(array);
-					return NULL;
-				}
-				for(int i=0; i<len; i++){
-					sprintf(&hexval[i*2], "%02X", ((uint8_t *)binval)[i]);
-				}
-				hexval[2*len] = '\0';
-				free(binval);
 
-				if(cJSON_AddStringToObject(obj, "value", hexval) == NULL){
+					if(cJSON_AddStringToObject(obj, "value", hexval) == NULL){
+						free(hexval);
+						cJSON_Delete(array);
+						return NULL;
+					}
 					free(hexval);
-					cJSON_Delete(array);
-					return NULL;
 				}
-				free(hexval);
 				break;
 
 			case MQTT_PROP_USER_PROPERTY: