usb: gadget: dummy_hcd: in transfer(), return data sent, not limit
usb: gadget: dummy_hcd: in transfer(), return data sent, not limit

dummy_timer uses transfer() to update transfer limit. However,
limit passed to dummy_timer changes depending on transfer type,
so the actual limit is overwritten.

This can cause unpredictably slow / fast bulk transfers when
coupled with control / interrupt transfers.

Fix by returning actual amount of data sent in transfer() and
substracting from total.

Signed-off-by: Igor Kotrasinski <5db3caed0e9bdd29b00baebff0d6fcd719efbc6c@samsung.com>
Signed-off-by: Felipe Balbi <94dddeeef08b001e003cce128ddc162a4e2c6cd2@ti.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs