compilation error at line 93 of librsvgdec.c

[S.C. Douglas]

Summary of the bug:
How to reproduce:
build against librsvg version less than 2.52

The following allows a build to finish but I have not checked against any test cases:
--- a/libavcodec/librsvgdec.c 2023-10-23 18:58:32.004460000 +0100
+++ b/libavcodec/librsvgdec.c 2023-10-23 19:57:06.170000000 +0100
@@ -90,8 +90,10 @@

goto end;

avctx->pix_fmt = AV_PIX_FMT_RGB32;

+#if LIBRSVG_MAJOR_VERSION > 2

LIBRSVG_MAJOR_VERSION == 2 && LIBRSVG_MINOR_VERSION >= 52

viewport.width = dimensions.width;
viewport.height = dimensions.height;

+#endif

ret = ff_get_buffer(avctx, frame, 0);
if (ret < 0)

[Balling]

build against librsvg version less than 2.52

86ed68420d3b60439d0b7767c53d0fdc1deb7277 says that older version should still be supported.