pkgdelta: use bsdtar -q option

This matches the optimization made to repo-add in commit 8bbaf045b9
way back in 2009. We don't need to read the whole package file to ensure
multiple .PKGINFO entries don't exist, as well-formed packages should
have this file first in the archive.

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

scripts/pkgdelta.sh.in

@@ -61,7 +61,7 @@ read_pkginfo()
 	IFS="
 "
 	local line var val
-	for line in $(bsdtar -xOf "$1" .PKGINFO 2>/dev/null |
+	for line in $(bsdtar -xOqf "$1" .PKGINFO 2>/dev/null |
 		grep -v "^#" | sed 's|\(\w*\)\s*=\s*\(.*\)|\1="\2"|'); do
 		eval "$line"
 		if [[ -n $pkgname && -n $pkgver && -n $arch ]]; then