cputest: Avoid use of temporary variable in DO_TEST macro

Use g_free directly to free the returned pointer from
virTestLogContentAndReset rather than store it in a temp variable which
was necessary when we only allowed VIR_FREE.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com

tests/cputest.c

@@ -997,10 +997,8 @@ mymain(void)
             flags, result \
         }; \
         char *testLabel; \
-        char *tmp; \
  \
-        tmp = virTestLogContentAndReset(); \
-        VIR_FREE(tmp); \
+        g_free(virTestLogContentAndReset());\
  \
         testLabel = g_strdup_printf("%s(%s): %s", #api, \
                                     virArchToString(arch), name); \