Remove unnecessary Kokoro workaround

Since we now force the version code of Linux builds, we do not need to
employ other workarounds to avoid it changing unexpectedly.

Change-Id: I8208e784c4f03ae87c6f09ee4223c0f179d59aa0
diff --git a/kokoro/build.sh b/kokoro/build.sh
index af59b9e..5a44b7e 100755
--- a/kokoro/build.sh
+++ b/kokoro/build.sh
@@ -63,15 +63,6 @@
 	shift
 done
 
-# Kokoro does something weird that makes all files look dirty to git diff-index;
-# this fixes it so that the Linux build doesn't think it has a dirty tree for
-# building the Hafnium kernel module (and so end up with a version magic string
-# that doesn't match the prebuilt kernel).
-(
-	cd third_party/linux &&
-	git status
-)
-
 #
 # Step 1: make sure it builds.
 #