Remove stray reference to error_at_rich_loc

"error_at_rich_loc" went away in r254280 (in favor of overloading
"error_at"), but there was a stray reference in a comment.

Remove it.

gcc/ChangeLog:
	* gcc-rich-location.h (gcc_rich_location::add_location_if_nearby):
	Fix usage of "error_at_rich_loc" in the comment.

From-SVN: r265177

gcc/ChangeLog

+2018-10-15  David Malcolm  <dmalcolm@redhat.com>
+
+	* gcc-rich-location.h (gcc_rich_location::add_location_if_nearby):
+	Fix usage of "error_at_rich_loc" in the comment.
+
 2018-10-15  Renlin Li  <renlin.li@arm.com>
 
 	PR target/87563

gcc/gcc-rich-location.h

@@ -56,7 +56,7 @@ class gcc_rich_location : public rich_location
 
 	gcc_rich_location richloc (primary_loc);
 	bool added secondary = richloc.add_location_if_nearby (secondary_loc);
-	error_at_rich_loc (&richloc, "main message");
+	error_at (&richloc, "main message");
 	if (!added secondary)
 	  inform (secondary_loc, "message for secondary");