makepkg: fix removing symbolic link

The path was not being stripped from $file before prefixing with
$srcdir resulting in the attempted removal of a very weird
filename.

Signed-off-by: Allan McRae <allan@archlinux.org>
Signed-off-by: Dan McGee <dan@archlinux.org>

scripts/makepkg.sh.in

@@ -518,7 +518,7 @@ download_sources() {
 		local file=$(get_filepath "$netfile" || true)
 		if [[ -n "$file" ]]; then
 			msg2 "$(gettext "Found %s")" "${file##*/}"
-			rm -f "$srcdir/$file"
+			rm -f "$srcdir/${file##*/}"
 			ln -s "$file" "$srcdir/"
 			continue
 		fi