Fix graphical glitches in volume adjustment menu

Due to the waitInputWithTimeout call taking up to 1 second, the framebuffer must be flushed. Also added padding where it was needed

sysmodules/rosalina/source/menus/sysconfig.c

@@ -443,6 +443,7 @@ void SysConfigMenu_AdjustVolume(void)
             posY = Draw_DrawString(30, posY, COLOR_WHITE, "\n                 ");
         }
 
+        Draw_FlushFramebuffer();
         u32 pressed = waitInputWithTimeout(1000);
 
         if(pressed & KEY_A)
@@ -484,6 +485,5 @@ void SysConfigMenu_AdjustVolume(void)
             if (tempVolumeOverride > 100)
                 tempVolumeOverride = 100;
         }
-
     } while(!menuShouldExit);
 }