ci: make shellcheck happy on dxvk script

Reviewed-by: "Sergi Blanch Torne" <sergi.blanch.torne@collabora.com>
Signed-off-by: David Heidelberg <david.heidelberg@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17887>

.gitlab-ci/container/install-wine-dxvk.sh

@@ -19,14 +19,14 @@ dxvk_install_pr() {
     # describe' is used by the dxvk build system to generate a
     # dxvk_version Meson variable, which is nice-to-have.
     git clone https://github.com/doitsujin/dxvk
-    pushd dxvk
+    pushd dxvk || exit 1
     git fetch origin pull/"$__prnum"/head:pr
     git checkout pr
     ./package-release.sh pr ../dxvk-build --no-package
-    popd
-    pushd ./dxvk-build/dxvk-pr
+    popd || exit 1
+    pushd ./dxvk-build/dxvk-pr || exit 1
     ./setup_dxvk.sh install
-    popd
+    popd || exit 1
     rm -rf ./dxvk-build ./dxvk
 }