via-velocity: add velocity_set_rxbufsize helper
via-velocity: add velocity_set_rxbufsize helper

It removes a dependancy from velocity_init_rd_ring to dev->mtu.

Signed-off-by: Francois Romieu <b6456b24ae82a7595be3173ae585c7a827f25f37@fr.zoreil.com>
Signed-off-by: Jeff Garzik <15f615bf7d20c2937c7eb5aa759110fd6768848c@redhat.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs