net: systemport: Free DMA coherent descriptors on errors

net: systemport: Free DMA coherent descriptors on errors

In case bcm_sysport_init_tx_ring() is not able to allocate ring->cbs, we
would return with an error, and call bcm_sysport_fini_tx_ring() and it
would see that ring->cbs is NULL and do nothing. This would leak the
coherent DMA descriptor area, so we need to free it on error before
returning.

Reported-by: Eric Dumazet <[email protected]>
Fixes: 80105befdb4b ("net: systemport: add Broadcom SYSTEMPORT Ethernet MAC driver")
Signed-off-by: Florian Fainelli <[email protected]>
Signed-off-by: David S. Miller <[email protected]>