Revert "Merge pull request #205 from bryongloden/patch-2"

This reverts commit 783fcaea97cf11975d75254742e800d7759fdbd0
 The guard memory bytes should never be freed inside unity_malloc()

extras/fixture/src/unity_fixture.c

@@ -207,9 +207,6 @@ void* unity_malloc(size_t size)
     mem = (char*)&(guard[1]);
     memcpy(&mem[size], end, sizeof(end));
 
-#ifndef UNITY_FIXTURE_MALLOC_OVERRIDES_H_
-    free(guard);
-#endif
     return (void*)mem;
 }