Versions of tar that don't know pax headers -- like the ones in NetBSD 6
and OpenBSD 5.2 -- extract them as regular files.  Explicitly ignore the
file created for our global header when checking the list of extracted
files, as this is normal and harmless fall-back behaviour.  This fixes
test 3 of t5004 on these platforms.
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>