ntlm: get rid of unconditional use of long long

... since some compilers don't have it and instead use other types, such
as __int64.

Reported by: gkinseyhpw
Closes #478

lib/curl_ntlm_core.c

@@ -664,21 +664,18 @@ CURLcode Curl_ntlm_core_mk_ntlmv2_resp(unsigned char *ntlmv2hash,
   unsigned int len = 0;
   unsigned char *ptr = NULL;
   unsigned char hmac_output[NTLM_HMAC_MD5_LEN];
-#if defined(HAVE_LONGLONG)
-  long long tw;
-#else
-  __int64 tw;
-#endif
+  curl_off_t tw;
+
   CURLcode result = CURLE_OK;
 
   /* Calculate the timestamp */
 #ifdef DEBUGBUILD
   char *force_timestamp = getenv("CURL_FORCETIME");
   if(force_timestamp)
-    tw = 11644473600ULL * 10000000ULL;
+    tw = (curl_off_t)11644473600 * 10000000;
   else
 #endif
-  tw = ((long long)time(NULL) + 11644473600ULL) * 10000000ULL;
+    tw = ((curl_off_t)time(NULL) + 11644473600) * 10000000;
 
   /* Calculate the response len */
   len = NTLM_HMAC_MD5_LEN + NTLMv2_BLOB_LEN;