charger: change the order of backlight control and fb blank

Backlight is getting disabled after fb blank is done. Change
the order to avoid transients and other issues.

Change-Id: Ie659ca76ab85e22ea2a3bc0da9b025785cb42511

charger/charger.c

@@ -795,8 +795,8 @@ static void update_screen_state(struct charger *charger, int64_t now)
     if (batt_anim->cur_cycle == batt_anim->num_cycles) {
         reset_animation(batt_anim);
         charger->next_screen_transition = -1;
-        gr_fb_blank(true);
         set_backlight(false);
+        gr_fb_blank(true);
 
 #ifdef ALLOW_SUSPEND_IN_CHARGER
         write_file(SYS_POWER_STATE, "mem", strlen("mem"));
@@ -1290,8 +1290,8 @@ int main(int argc, char **argv)
     ev_sync_key_state(set_key_callback, charger);
 
 #ifndef CHARGER_DISABLE_INIT_BLANK
-    gr_fb_blank(true);
     set_backlight(false);
+    gr_fb_blank(true);
 #endif
 
     charger->next_screen_transition = now - 1;