scripts/feeds: fix 'src-include' directive

Commit 775b70f8d5 renamed parse_file() parameters without
updating the recursive call. This broke parsing of any feeds.conf
using 'src-include'.

 $ scripts/feeds update -a
 Can't use string ("defaults") as a HASH ref while "strict refs" in use at scripts/feeds line 63, <$fh> line 1.

Fixes: 775b70f8d5 ("scripts/feeds: allow adding parameters to feeds")
Signed-off-by: Bjørn Mork <bjorn@mork.no>

scripts/feeds

@@ -75,7 +75,7 @@ sub parse_file($$) {
 		}
 
 		if ($type eq "include") {
-			parse_file($urls, $name) or
+			parse_file($urls, $existing) or
 			    die "Unable to open included file '$urls'";
 			next;
 		}