[PATCH] windowscodecs/tests: Use winetest_push_context for DDS tests.

[Ziqing Hui]

Signed-off-by: Ziqing Hui <zhui(a)codeweavers.com>
---
 dlls/windowscodecs/tests/ddsformat.c | 291 ++++++++++++++-------------
 1 file changed, 151 insertions(+), 140 deletions(-)