[mutter] tests/kvm: Disable -Werror when building kernel image

[Marge Bot <marge-bot src gnome org>]

commit d371c1803589992c54269f664105cd1879779787
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Jul 8 03:11:02 2022 +0200

    tests/kvm: Disable -Werror when building kernel image
    
    We aren't kernel developers, and we won't fix any new warnings
    that appear after a compiler update, in particular when building
    a CI image.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2430>

 src/tests/kvm/build-linux.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/tests/kvm/build-linux.sh b/src/tests/kvm/build-linux.sh
index 49f622a567..2dd28b4059 100755
--- a/src/tests/kvm/build-linux.sh
+++ b/src/tests/kvm/build-linux.sh
@@ -63,7 +63,7 @@ echo Enabling ${CONFIGS[@]}...
 ./scripts/config ${CONFIGS[@]/#/--enable }
 
 make oldconfig
-make -j8
+make -j8 WERROR=0
 
 popd