xbps-src: replace basename(1) with ${var##*/}.

Reduce number of fork+exec due to using a subshell to execute basename(1).

common/hooks/post-install/00-compress-info-files.sh

@@ -32,7 +32,7 @@ hook() {
 		if [ -h ${PKGDESTDIR}/"$j" ]; then
 			dirat=$(dirname "$j")
 			lnkat=$(readlink ${PKGDESTDIR}/"$j")
-			newlnk=$(basename "$j")
+			newlnk="${j##*/}"
 			rm -f ${PKGDESTDIR}/"$j"
 			cd ${PKGDESTDIR}/"$dirat"
 			ln -s "${lnkat}".gz "${newlnk}".gz