Revert "kheaders: Ignore silly-rename files"

This reverts commit 973b710b.

As I mentioned in the review [1], I do not believe this was the correct
fix.

Commit 41a00051 ("kheaders: prevent `find` from seeing perl temp
files") addressed the root cause of the issue. I asked David to test
it but received no response.

Commit 973b710b ("kheaders: Ignore silly-rename files") merely
worked around the issue by excluding such files, rather than preventing
their creation.

I have reverted the latter commit, hoping the issue has already been
resolved by the former. If the silly-rename files come back, I will
restore this change (or preferably, investigate the root cause).

[1]: https://lore.kernel.org/lkml/CAK7LNAQndCMudAtVRAbfSfnV+XhSMDcnP-s1_GAQh8UiEdLBSg@mail.gmail.com/



Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>