Curl_pgrsDone: return int and acknowledge return code

Since Curl_pgrsDone() itself calls Curl_pgrsUpdate() which may return an
abort instruction or similar we need to return that info back and
subsequently properly handle return codes from Curl_pgrsDone() where
used.

(Spotted by a Coverity scan)

lib/url.c

@@ -5379,7 +5379,8 @@ CURLcode Curl_done(struct connectdata **connp,
   else
     result = CURLE_OK;
 
-  Curl_pgrsDone(conn); /* done with the operation */
+  if(Curl_pgrsDone(conn) && !result)
+    result = CURLE_ABORTED_BY_CALLBACK;
 
   /* if the transfer was completed in a paused state there can be buffered
      data left to write and then kill */