UPSTREAM: USB: gadget: validate interface OS descriptor requests

Stall the control endpoint in case provided index exceeds array size of
MAX_CONFIG_INTERFACES or when the retrieved function pointer is null.

Bug: 213172319
Signed-off-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 75e5b484)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I78f46b6f2140394a6bc6cff9f829c0742d7ad2fc