echo kabi check output on failure

Author: bmastbergen

.github/workflows/build-check_x86_64.yml

@@ -38,6 +38,7 @@ jobs:
           git -C kernel-dist-git reset --hard imports/r9/kernel-5.14.0-284.30.1.el9_2
           KABI_CHECK=$(./kernel-dist-git/SOURCES/check-kabi -k ./kernel-dist-git/SOURCES/Module.kabi_x86_64 -s Module.symvers)
           if [ $? -ne 0 ]; then
+              echo ${KABI_CHECK}
               echo "Error: kABI check failed"
               exit 1
           fi