checkapk: treat subpackages items as colon separated lists

fixes to pick correct subpackage name when "pkg:split:arch" syntax
is used.

checkapk.in

@@ -50,7 +50,7 @@ tmpdir=$(mktemp -d -t checkpkg-script.XXXXXX)
 cd "$tmpdir" || die "failed to create temp dir"
 
 for i in $pkgname $subpackages; do
-	_pkgname=${i%:*}
+	_pkgname=${i%%:*}
 	pkg=${_pkgname}-$pkgver-r$pkgrel
 	pkgfile=${pkg}.apk
 	repodir=${startdir%/*}