ref_gl: fix loop scope in ripple code

ref/gl/gl_warp.c

@@ -968,6 +968,7 @@ void R_UploadRipples( texture_t *image )
 	gl_texture_t *glt;
 	uint32_t *pixels;
 	int wbits, wmask, wshft;
+	int y;
 
 	// discard unuseful textures
 	if( !r_ripple.value || image->width > RIPPLES_CACHEWIDTH || image->width != image->height )
@@ -1005,11 +1006,12 @@ void R_UploadRipples( texture_t *image )
 	wshft = 7 - wbits;
 	wmask = image->width - 1;
 
-	for( int y = 0; y < image->height; y++ )
+	for( y = 0; y < image->height; y++ )
 	{
 		int ry = y << ( 7 + wshft );
+		int x;
 
-		for( int x = 0; x < image->width; x++ )
+		for( x = 0; x < image->width; x++ )
 		{
 			int rx = x << wshft;
 			int val = g_ripple.curbuf[ry + rx] >> 4;