usb: isp1760: remove redundant max_packet() macro

usb: isp1760: remove redundant max_packet() macro

The function usb_endpoint_maxp() (called by usb_maxpacket()) already
does the sanitazation of the USB endpoint max packet size. The call to
max_packet() does the same thing and is thus removed.

The macro max_packet() not being used anymore also gets removed.

Reviewed-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20220306075524.706660-3-mailhol.vincent@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>