add cd kernel to change Kbuild

.github/actions/ksun/action.yml

@@ -49,6 +49,7 @@ runs:
         KSU_COMMIT=$(git rev-parse --short refs/remotes/origin/dev 2>/dev/null)
         KSU_VERSION=$((30000 + KSU_GIT_VERSION))
 
+        cd kernel
         sed -i "s/^KSU_VERSION_FALLBACK := 1$/KSU_VERSION_FALLBACK := ${KSU_VERSION}/" Kbuild
         sed -i "s/^KSU_VERSION_TAG_FALLBACK := v0.0.1$/KSU_VERSION_TAG_FALLBACK := ${KSU_GIT_TAG}/" Kbuild