Cleanup: replace members m_ prefix by _ suffix in Compositor

To convert old code to the current convention and
use a single code style.

source/blender/compositor/operations/COM_VectorCurveOperation.h

@@ -28,7 +28,7 @@ class VectorCurveOperation : public CurveBaseOperation {
   /**
    * Cached reference to the inputProgram
    */
-  SocketReader *m_inputProgram;
+  SocketReader *inputProgram_;
 
  public:
   VectorCurveOperation();