lineedit: fix SEGV in isk, hexedit, ed, closes 11661

fdisk, hexedit and ed calls read_line_edit in libbb/lineedit.c with NULL
as first argument. On line 2373 of lineedit.c of busybox version 1.29.3,
state->hist_file is referenced without checking the state->flag.

This causes segmentation fault on fdisk, hexedit and ed on ARM Cortex-A9.
It somehow works on x86_64.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 0a888fa..1d5fef5 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -2383,13 +2383,14 @@
 		timeout = st->timeout;
 	}
 #if MAX_HISTORY > 0
+	if (state->flags & DO_HISTORY) {
 # if ENABLE_FEATURE_EDITING_SAVEHISTORY
-	if (state->hist_file)
-		if (state->cnt_history == 0)
-			load_history(state);
+		if (state->hist_file)
+			if (state->cnt_history == 0)
+				load_history(state);
 # endif
-	if (state->flags & DO_HISTORY)
 		state->cur_history = state->cnt_history;
+	}
 #endif
 
 	/* prepare before init handlers */