Improve check to apply X265 API workaround

Not a perfect check, since the commit in the x265 repo that introduces
it doesn't bump the X265_BUILD constant like it probably should have.

There's still a range of x265 commits from 2024-10-04 to 2024-11-12
where fceux will not build against the development version of x265. If
that's the case, just update to the latest x265.

Research shows:

https://bitbucket.org/multicoreware/x265_git@c8c9d22075b26aa279b4d634c61889ca3d49656e:
- X265_BUILD: 209 -> 210
- MAX_SCALABLE_LAYERS: undefined

https://bitbucket.org/multicoreware/x265_git@c69c113960834400545bc4bce2830ff51dcb86b3:
- API change introduced; workaround needed
- X265_BUILD: 210
- MAX_SCALABLE_LAYERS: defined

https://bitbucket.org/multicoreware/x265_git@78e5b703b186fe184bf91bb37df82f64059b3f61:
- API change reverted; using our workaround now breaks the fceux build
- X265_BUILD: 213
- MAX_SCALABLE_LAYERS: still defined

https://bitbucket.org/multicoreware/x265_git@451add89e81d45134b9d41168ceeb5516bf62d0b:
- X265_BUILD: 213 -> 214
- MAX_SCALABLE_LAYERS: still defined
- Using our workaround still breaks the fceux build

src/drivers/Qt/AviRecord.cpp

@@ -461,8 +461,8 @@ static int encode_frame( unsigned char *inBuf, int width, int height )
 	pic->stride[1] = width/2;
 	pic->stride[2] = width/2;
 
-#ifdef MAX_SCALABLE_LAYERS
-	/* Handle API changes for scalable layers output in x265 4.0 */
+#if X265_BUILD >= 210 && X265_BUILD <= 213 && defined(MAX_SCALABLE_LAYERS)
+	/* Handle temporary API changes for scalable layers output in x265 4.0 */
 	x265_picture *pics[MAX_SCALABLE_LAYERS] = {NULL};
 	pics[0] = pic;
 	ret = x265_encoder_encode( hdl, &nal, &i_nal, pic, pics );
@@ -501,8 +501,8 @@ static int close(void)
 	/* Flush delayed frames */
 	while( hdl != NULL )
 	{
-#ifdef MAX_SCALABLE_LAYERS
-	    /* Handle API changes for scalable layers output in x265 4.0 */
+#if X265_BUILD >= 210 && X265_BUILD <= 213 && defined(MAX_SCALABLE_LAYERS)
+	    /* Handle temporary API changes for scalable layers output in x265 4.0 */
 	    x265_picture *pics[MAX_SCALABLE_LAYERS] = {NULL};
 	    pics[0] = pic;
 	    ret = x265_encoder_encode( hdl, &nal, &i_nal, pic, pics );