Fix a timing issue in kasp system test

Sometimes, not all keys have been created in time before 'check_keys'
is called. Run a 'retry_quiet' on checking the number of keys before
continuing checking the key data.

(cherry picked from commit af3b014976)

bin/tests/system/kasp/tests.sh

@@ -833,23 +833,30 @@ status=$((status+ret))
 
 next_key_event_threshold=$((next_key_event_threshold+i))
 
+check_numkeys() {
+	_numkeys=$(get_keyids "$1" "$2" | wc -l)
+	test "$_numkeys" -eq "$NUM_KEYS" || return 1
+	return 0
+}
+
 # Check keys for a configured zone. This verifies:
 # 1. The right number of keys exist in the key pool ($1).
 # 2. The right number of keys is active. Checks KEY1, KEY2, KEY3, and KEY4.
 #
 # It is expected that KEY1, KEY2, KEY3, and KEY4 arrays are set correctly.
 # Found key identifiers are stored in the right key array.
-check_keys()
-{
+check_keys() {
 	n=$((n+1))
 	echo_i "check keys are created for zone ${ZONE} ($n)"
 	ret=0
 
 	echo_i "check number of keys for zone ${ZONE} in dir ${DIR} ($n)"
-	_numkeys=$(get_keyids "$DIR" "$ZONE" | wc -l)
-	test "$_numkeys" -eq "$NUM_KEYS" || log_error "bad number ($_numkeys) of key files for zone $ZONE (expected $NUM_KEYS)"
-	test "$ret" -eq 0 || echo_i "failed"
-	status=$((status+ret))
+	retry_quiet 10 check_numkeys "$DIR" "$ZONE" "$NUM_KEYS" || ret=1
+	if [ $ret -ne 0 ]; then
+		_numkeys=$(get_keyids "$1" "$2" | wc -l)
+		log_error "bad number of key files ($_numkeys) for zone $ZONE (expected $NUM_KEYS)"
+		status=$((status+ret))
+	fi
 
 	# Temporarily don't log errors because we are searching multiple files.
 	_log=0