Remove incorrect address-of on instance pointer to delete

This was causing a segfault, due to trying to delete the stack address
of the pointer itself.

Signed-off-by: Anna Rift <[email protected]>

test/types/cptr/useChplClassInC/useChplClassInC.test.c

@@ -16,7 +16,7 @@ int main(int argc, char** argv) {
   void* fooInstance; // class Foo in Chapel, but we only use a void* to it
   getInstance(&fooInstance, 4);
   printf("%i\n", useInstance(fooInstance));
-  deleteInstance(&fooInstance);
+  deleteInstance(fooInstance);
 
   chpl_library_finalize();
 }