gitlab-ci: Always set libdir to lib/

I introduced libdir for cross-builds so we could point at the
resulting drivers without per-arch dependencies, but I'd rather not
have to type x86_64-linux-whatever for non-cross-builds either.

Reviewed-by: Eric Engestrom <eric@engestrom.ch>

.gitlab-ci.yml

@@ -247,7 +247,6 @@ meson-vulkan:
       -D gallium-nine=false
       -D llvm=false
     CROSS: >
-      --libdir lib
       --cross /tmp/cross_file.txt
 
   script:

.gitlab-ci/meson-build.sh

@@ -17,6 +17,7 @@ fi
 rm -rf _build
 meson _build --native-file=native.file \
       ${CROSS} \
+      -D libdir=lib \
       -D buildtype=debug \
       -D build-tests=true \
       -D libunwind=${UNWIND} \