Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_PSP

src/render/SDL_render.c

@@ -110,7 +110,7 @@ static const SDL_RenderDriver *render_drivers[] = {
 #ifdef SDL_VIDEO_RENDER_PS2
     &PS2_RenderDriver,
 #endif
-#if SDL_VIDEO_RENDER_PSP
+#ifdef SDL_VIDEO_RENDER_PSP
     &PSP_RenderDriver,
 #endif
 #if SDL_VIDEO_RENDER_VITA_GXM

src/render/psp/SDL_render_psp.c

@@ -20,7 +20,7 @@
 */
 #include "SDL_internal.h"
 
-#if SDL_VIDEO_RENDER_PSP
+#ifdef SDL_VIDEO_RENDER_PSP
 
 #include "../SDL_sysrender.h"