SDL: Fixed n3ds build (c77aa)

SDL Commits
1 
From c77aaa5d996e4c396641135128e620d294528a84 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Mon, 12 Jun 2023 15:39:57 -0700
Subject: [PATCH] Fixed n3ds build

(cherry picked from commit d95dbe78bb7a5087ecfb8d301417b1108d868738)
---
 src/joystick/SDL_joystick.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/joystick/SDL_joystick.c b/src/joystick/SDL_joystick.c
index 02d7eddab3de..8bdf952b0ebe 100644
--- a/src/joystick/SDL_joystick.c
+++ b/src/joystick/SDL_joystick.c
@@ -144,9 +144,9 @@ SDL_bool SDL_JoysticksQuitting(void)
 
 void SDL_LockJoysticks(void)
 {
-    SDL_AtomicIncRef(&SDL_joystick_lock_pending);
+    (void)SDL_AtomicIncRef(&SDL_joystick_lock_pending);
     SDL_LockMutex(SDL_joystick_lock);
-    SDL_AtomicDecRef(&SDL_joystick_lock_pending);
+    (void)SDL_AtomicDecRef(&SDL_joystick_lock_pending);
 
     ++SDL_joysticks_locked;
 }