cmd: Incorrect usage of realloc

base\shell\cmd\path.c 63 error Common realloc mistake: 'pszBuffer' nulled but not freed upon failure
base\shell\cmd\where.c 155 error Common realloc mistake: 'pszPathExt' nulled but not freed upon failure
base\shell\cmd\where.c 187 error Common realloc mistake: 'pszPath' nulled but not freed upon failure

for more information please refer to http://www.cplusplus.com/reference/cstdlib/realloc/