Fix compilation issue with VS6:
Fix compilation issue with VS6:

y:\github\paulbussmann\cpputest\src\cpputest\memoryleakdetector.cpp(81) : error C2374: 'p' : redefinition; multiple initialization
        y:\github\paulbussmann\cpputest\src\cpputest\memoryleakdetector.cpp(75) : see declaration of 'p'
y:\github\paulbussmann\cpputest\src\cpputest\memoryleakdetector.cpp(89) : error C2374: 'p' : redefinition; multiple initialization
        y:\github\paulbussmann\cpputest\src\cpputest\memoryleakdetector.cpp(75) : see declaration of 'p'

bithium/cpputest,offa/cpputest,asgeroverby/cpputest,cpputest/cpputest,basvodde/cpputest,basvodde/cpputest,offa/cpputest,bithium/cpputest,maxilai/cpputest,KisImre/cpputest,maxilai/cpputest,Mindtribe/cpputest,maxilai/cpputest,offa/cpputest,jaeguly/cpputest,maxilai/cpputest,cpputest/cpputest,PaulBussmann/cpputest,arstrube/cpputest,Andne/cpputest,jaeguly/cpputest,PaulBussmann/cpputest,bithium/cpputest,basvodde/cpputest,cpputest/cpputest,Andne/cpputest,Mindtribe/cpputest,jaeguly/cpputest,Andne/cpputest,KisImre/cpputest,asgeroverby/cpputest,arstrube/cpputest,Mindtribe/cpputest,KisImre/cpputest,PaulBussmann/cpputest,asgeroverby/cpputest,arstrube/cpputest,Mindtribe/cpputest,PaulBussmann/cpputest,offa/cpputest,asgeroverby/cpputest,jaeguly/cpputest,KisImre/cpputest,arstrube/cpputest,cpputest/cpputest,basvodde/cpputest,Andne/cpputest,bithium/cpputest