gpg: close stderr once finished with it in verify_signed_buffer()
Failing to close the stderr pipe in verify_signed_buffer() causes
git to run out of file descriptors if there are many calls to
verify_signed_buffer(). An easy way to trigger this is to run
git log --show-signature --merges | grep "key"
on the linux kernel git repo. Eventually it will fail with
error: cannot create pipe for gpg: Too many open files
error: could not run gpg.
Close the stderr pipe so that this can't happen.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>