usb: gadget: Fixed QMI packets error handling

When notify packet transfer failed, notify_count and cpkt_resp_q
would go out of sync. After the fix the packets are also removed from
the queue.

Change-Id: If33ea5070f460617179a77063a9e58c47ed93167
CRs-Fixed: 383661
Signed-off-by: Anna Perel <aperel@codeaurora.org>