evr: Fix incorrect integral computation.

Note: typeof (int * unsigned) is unsigned.
So:
- on 64bit CPUs, where sizeof(int) = 4 < sizeof(void*) = 8,
- when the result of the multiplication is supposed to be negative
- there's no propagation of the negative sign from 32bit to 64 bit integers

Fixes a crash in Age of Empire II.

Signed-off-by: Eric Pouech <epouech@codeweavers.com>

dlls/evr/evr.c

@@ -382,7 +382,7 @@ static HRESULT evr_copy_sample_buffer(struct evr *filter, IMediaSample *input_sa
         {
             if (SUCCEEDED(hr = IDirect3DSurface9_LockRect(surface, &locked_rect, NULL, D3DLOCK_DISCARD)))
             {
-                if (src_stride < 0) src -= src_stride * (lines - 1);
+                if (src_stride < 0) src += (-src_stride) * (lines - 1);
                 MFCopyImage(locked_rect.pBits, locked_rect.Pitch, src, src_stride, width * 4, lines);
                 IDirect3DSurface9_UnlockRect(surface);
             }