Free some memory on error eclipse-paho#882

Author: icraggs

src/MQTTAsync.c

@@ -3785,12 +3785,15 @@ int MQTTAsync_send(MQTTAsync handle, const char* destinationName, int payloadlen
 	}
 	if ((pub->command.details.pub.destinationName = MQTTStrdup(destinationName)) == NULL)
 	{
+		free(pub);
 		rc = PAHO_MEMORY_ERROR;
 		goto exit;
 	}
 	pub->command.details.pub.payloadlen = payloadlen;
 	if ((pub->command.details.pub.payload = malloc(payloadlen)) == NULL)
 	{
+		free(pub->command.details.pub.destinationName);
+		free(pub);
 		rc = PAHO_MEMORY_ERROR;
 		goto exit;
 	}