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/progress.c

@@ -131,11 +131,14 @@ static char *max5data(curl_off_t bytes, char *max5)
 
 */
 
-void Curl_pgrsDone(struct connectdata *conn)
+int Curl_pgrsDone(struct connectdata *conn)
 {
+  int rc;
   struct SessionHandle *data = conn->data;
   data->progress.lastshow=0;
-  Curl_pgrsUpdate(conn); /* the final (forced) update */
+  rc = Curl_pgrsUpdate(conn); /* the final (forced) update */
+  if(rc)
+    return rc;
 
   if(!(data->progress.flags & PGRS_HIDE) &&
      !data->progress.callback)
@@ -144,6 +147,7 @@ void Curl_pgrsDone(struct connectdata *conn)
     fprintf(data->set.err, "\n");
 
   data->progress.speeder_c = 0; /* reset the progress meter display */
+  return 0;
 }
 
 /* reset all times except redirect, and reset the known transfer sizes */
@@ -241,6 +245,10 @@ void Curl_pgrsSetUploadSize(struct SessionHandle *data, curl_off_t size)
     data->progress.flags &= ~PGRS_UL_SIZE_KNOWN;
 }
 
+/*
+ * Curl_pgrsUpdate() returns 0 for success or the value returned by the
+ * progress callback!
+ */
 int Curl_pgrsUpdate(struct connectdata *conn)
 {
   struct timeval now;