USB: s3c-hsotg: Fix hang up after reset

When File Storage gadget receives SET CONFIGURATION request it tries
to cancel all pending transfers. If some request is in progress,
gadget waits for its completion. This commit allows gadget to dequeue
invalid requests in progress left after reset.

Signed-off-by: Anton Tikhomirov <av.tikhomirov@samsung.com>
Reviewed-by: Kyoungil Kim<ki0351.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>