use template when generating tempdir in verify-crds

Due to a bug in controller-gen[1] certain paths are incorrectly split
and part of these paths can be interpreted as a numeric literal, which
will cause controller-gen to fail. We observe this as occasional test
flakes in the "verify-crds" target, when the tmpdir starts with a zero,
such as in "/tmp/tmp.0PFqFSHBID"

This commit attempts to avoid this bug by specifying a template for the
tmpdir we generate when verifying CRDs which doesn't include any "."
characters, which seem to be being split incorrectly.

[1] kubernetes-sigs/controller-tools#734

Signed-off-by: Ashley Davis <[email protected]>

hack/check-crds.sh

@@ -41,7 +41,7 @@ fi
 
 echo "+++ verifying that generated CRDs are up-to-date..." >&2
 
-tmpdir="$(mktemp -d)"
+tmpdir="$(mktemp -d tmp-CHECKCRD-XXXXXXXXX --tmpdir)"
 trap 'rm -r $tmpdir' EXIT
 
 make PATCH_CRD_OUTPUT_DIR=$tmpdir patch-crds