Made unit_setup() return an error code to abort the test early

This makes it possible to skip the call to unit_stop() in such
cases.  Also use Curl_safefree() in unit test 1302 so it will
pass the memory torture test.

tests/unit/unit1301.c

@@ -5,7 +5,7 @@
 #include "strequal.h"
 #include "curlcheck.h"
 
-static void unit_setup( void ) {}
+static CURLcode unit_setup( void ) {return CURLE_OK;}
 static void unit_stop( void ) {}
 
 UNITTEST_START