patch 8.1.2222: accessing invalid memory

Problem:    Accessing invalid memory. (Dominique Pelle)
Solution:   Reset highlight_match every time.  (closes #5125)
diff --git a/src/ex_getln.c b/src/ex_getln.c
index 45a0a36..9c98f99 100644
--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -525,6 +525,7 @@
 	curwin->w_redr_status = TRUE;
 
     update_screen(SOME_VALID);
+    highlight_match = FALSE;
     restore_last_search_pattern();
 
     // Leave it at the end to make CTRL-R CTRL-W work.  But not when beyond the
@@ -642,6 +643,7 @@
 	highlight_match = TRUE;
 	save_viewstate(&is_state->old_viewstate);
 	update_screen(NOT_VALID);
+	highlight_match = FALSE;
 	redrawcmdline();
 	curwin->w_cursor = is_state->match_end;
     }