Revert "make sure we're building for the correct kernel version"

This reverts commit 6116cb3a527a6176bbadf6b418c45f3ffa6eb45a.

.github/workflows/ci.yml

@@ -14,4 +14,4 @@ jobs:
     - name: prepare build
       run: sudo m-a prepare
     - name: build
-      run: make KVER=$KVER
+      run: make