Use delete[] instead of delete for sampleFrame

Fixes warning: 'delete' applied to a pointer-to-array type 'sampleFrame *' (aka 'sample_t (*)[2]') treated as delete[] in mac os build

plugins/delay/stereodelay.cpp

@@ -48,7 +48,7 @@ StereoDelay::~StereoDelay()
 {
 	if( m_buffer )
 	{
-		delete m_buffer;
+		delete[] m_buffer;
 	}
 }
 
@@ -84,7 +84,7 @@ void StereoDelay::setSampleRate( int sampleRate )
 {
 	if( m_buffer )
 	{
-		delete m_buffer;
+		delete[] m_buffer;
 	}
 
 	int bufferSize = ( int )( sampleRate * m_maxTime );