Revert "sdelay: reduce function to just one line" due to supposed Bashism.

This reverts commit f03de62e7d.

defaults/initrd.scripts

@@ -883,7 +883,12 @@ startLUKS() {
 sdelay() {
 	# Sleep a specific number of seconds if SDELAY is set otherwise only sleep
 	# 3 seconds, which is a much better default than 1 second (previous default)
-	sleep ${SDELAY:-3}
+	if [ "${SDELAY}" ]
+	then
+		sleep ${SDELAY}
+	else
+		sleep 3
+	fi
 }
 
 quiet_kmsg() {