Cast nullptr to const void* to satisfy picky compilers

common/gal/opengl/utils.cpp

@@ -84,7 +84,7 @@ int checkGlError( const std::string& aInfo, bool aThrow )
 
 
 static void debugMsgCallback( GLenum aSource, GLenum aType, GLuint aId,
-   GLenum aSeverity, GLsizei aLength, const GLchar* aMessage, const void* aUserParam) 
+   GLenum aSeverity, GLsizei aLength, const GLchar* aMessage, const void* aUserParam )
 {
     printf( "%s", aMessage );
 }
@@ -95,7 +95,7 @@ void enableGlDebug( bool aEnable )
     if( aEnable )
     {
         glEnable( GL_DEBUG_OUTPUT );
-        glDebugMessageCallback( debugMsgCallback, nullptr );
+        glDebugMessageCallback( debugMsgCallback, (const void*) nullptr );
     }
     else
     {