ash: randmconfig fix

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash.c b/shell/ash.c
index 1cfef27..dac7318 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -13301,7 +13301,7 @@
 	}
 
 	if (sflag || minusc == NULL) {
-#if MAX_HISTORY > 0 && ENABLE_FEATURE_EDITING_SAVEHISTORY
+#if defined MAX_HISTORY && MAX_HISTORY > 0 && ENABLE_FEATURE_EDITING_SAVEHISTORY
 		if (iflag) {
 			const char *hp = lookupvar("HISTFILE");
 			if (hp)