tests: Fix memory leak in mymain

Commit d2899a64 added a new exit path, but didn't free @fakerootdir.
Let's just use VIR_AUTOFREE instead to make life easier.

Found by Coverity
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

tests/virhostdevtest.c

@@ -556,7 +556,7 @@ static int
 mymain(void)
 {
     int ret = 0;
-    char *fakerootdir;
+    VIR_AUTOFREE(char *) fakerootdir = NULL;
 
     if (VIR_STRDUP_QUIET(fakerootdir, FAKEROOTDIRTEMPLATE) < 0) {
         fprintf(stderr, "Out of memory\n");
@@ -594,8 +594,6 @@ mymain(void)
     if (getenv("LIBVIRT_SKIP_CLEANUP") == NULL)
         virFileDeleteTree(fakerootdir);
 
-    VIR_FREE(fakerootdir);
-
     return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
 }