Add missing initializers to sound classes

src/sound/oalsound/channel.cpp

@@ -22,6 +22,7 @@
 
 Channel::Channel()
     : m_buffer(nullptr),
+      m_source(0),
       m_priority(0),
       m_id(0),
       m_startAmplitude(0.0f),

src/sound/oalsound/channel.h

@@ -38,11 +38,11 @@
 
 struct SoundOper
 {
-    float finalAmplitude;
-    float finalFrequency;
-    float totalTime;
-    float currentTime;
-    SoundNext nextOper;
+    float finalAmplitude = 0.0f;
+    float finalFrequency = 0.0f;
+    float totalTime = 0.0f;
+    float currentTime = 0.0f;
+    SoundNext nextOper = {};
 };