Remove Ksh'isms. There is no need for it, so use regular Bourne

Shell constructs.

openup

@@ -101,8 +101,9 @@ pr_smallarrow() {
 get_cert() {
 	local _CMD
 
-	[[ -r /etc/ssl/pkgca.pem ]] && \
+	if [ -r /etc/ssl/pkgca.pem ]; then
 		split -p '^-----BEGIN CERTIFICATE-----$' /etc/ssl/pkgca.pem ${_TMPSPLITCERT}
+	fi
 
 	for i in ${_TMPSPLITCERT}* ; do
 		openssl x509 -noout -in $i -fingerprint 2>/dev/null | \
@@ -214,15 +215,15 @@ done
 [ $# = $(($OPTIND-1)) ] || usage
 
 if [ -z "${checkmode}" ]; then
-	[[ -z $noselfupdate ]] && update_self
-	[[ -z $nosig ]] && get_cert
+	if [ -z $noselfupdate ]; then update_self; fi
+	if [ -z $nosig ]; then get_cert; fi
 	update_binpatches
 	update_pkg
 else
 	if [ "${nosig}" -o "${noselfupdate}" -o "${dryrun}" -a -z "${_RUN2}" ]; then
 		usage
 	fi
-	[[ -z $noselfupdate ]] && update_self >/dev/null
+	if [ -z $noselfupdate ]; then update_self >/dev/null; fi
 	check_vuxml
 fi