fix crash in Test_BitonicSort

test/OpenCL/BitonicSort/main.cpp

@@ -69,6 +69,8 @@ int main(int argc, char* argv[])
 		
 		cl_context context = b3OpenCLUtils::createContextFromPlatform(platform,deviceType,&ciErrNum);
 		
+		if (context)
+		{
 			int numDevices = b3OpenCLUtils::getNumDevices(context);
 			printf("Num Devices = %d\n", numDevices);
 			for (int j=0;j<numDevices;j++)
@@ -146,6 +148,7 @@ int main(int argc, char* argv[])
 
 			clReleaseContext(context);
 		}
+	}
 
 	///Easier method to initialize OpenCL using createContextFromType for a GPU
 	deviceType = CL_DEVICE_TYPE_GPU;