sound: fix volume change being reported to %mv tag on boot

Setting the last_volume_change time was moved here in
commit 2e08b0f82e ("sound: update global volume state
in sound_set_volume()"); however this also triggers the
%mv tag on boot, as if the user was actively changing
the volume.

Move the last_volume_change update back to the original
call sites to fix this.

Change-Id: I895112cea4315f194f67c27839f1082d67c1ffa9

apps/gui/option_select.c

@@ -594,6 +594,9 @@ bool option_screen(const struct settings_list *setting,
             if (!cb_on_changed || (*variable != oldvalue))
             {
                 function(*variable);
+                /* if the volume is changing we need to let the skins know */
+                if (function == sound_get_fn(SOUND_VOLUME))
+                    global_status.last_volume_change = current_tick;
             }
         }
 

apps/misc.c

@@ -879,6 +879,7 @@ void setvol(void)
         volume = global_settings.volume_limit;
 
     sound_set_volume(volume);
+    global_status.last_volume_change = current_tick;
     status_save(false);
 }