Commit 3e4f8e21 ("USB: core: fix check for duplicate endpoints")
aimed to make the USB stack more reliable by detecting and skipping
over endpoints that are duplicated between interfaces.  This caused a
regression for a Hercules audio card (reported as Bugzilla #208357),
which contains such non-compliant duplications.  Although the
duplications are harmless, skipping the valid endpoints prevented the
device from working.

This patch fixes the regression by adding ENDPOINT_IGNORE quirks for
the Hercules card, telling the kernel to ignore the invalid duplicate
endpoints and thereby allowing the valid endpoints to be used as
intended.

Fixes: 3e4f8e21 ("USB: core: fix check for duplicate endpoints")
CC: <stable@vger.kernel.org>
Reported-by: Alexander Chalikiopoulos <bugzilla.kernel.org@mrtoasted.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20201119170040.GA576844@rowland.harvard.eduSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>