Fix the mutex logic in fifo.c from the espeak_ng_STATUS changes.

src/libespeak-ng/fifo.c

@@ -95,8 +95,10 @@ espeak_ng_STATUS fifo_add_command(t_espeak_command *the_command)
 	if ((status = pthread_mutex_lock(&my_mutex)) != ENS_OK)
 		return status;
 
-	if ((status = push(the_command)) != ENS_OK)
+	if ((status = push(the_command)) != ENS_OK) {
+		pthread_mutex_unlock(&my_mutex);
 		return status;
+	}
 
 	if ((status = pthread_mutex_unlock(&my_mutex)) != ENS_OK)
 		return status;
@@ -124,11 +126,15 @@ espeak_ng_STATUS fifo_add_commands(t_espeak_command *command1, t_espeak_command
 	if (node_counter+1 >= MAX_NODE_COUNTER)
 		return ENS_FIFO_BUFFER_FULL;
 
-	if ((status = push(command1)) != ENS_OK)
+	if ((status = push(command1)) != ENS_OK) {
+		pthread_mutex_unlock(&my_mutex);
 		return status;
+	}
 
-	if ((status = push(command2)) != ENS_OK)
+	if ((status = push(command2)) != ENS_OK) {
+		pthread_mutex_unlock(&my_mutex);
 		return status;
+	}
 
 	if ((status = pthread_mutex_unlock(&my_mutex)) != ENS_OK)
 		return status;