net/bnxt: fix a memory leak in port stop

net/bnxt: fix a memory leak in port stop

The memory for mark table is allocated during port start.
But the allocated memory is freed only during port close
or driver unload which in turn causes a memory leakage
on each port start/stop.

Fixed it by moving the memory free to port stop.

Fixes: 94eb699bc82e ("net/bnxt: support flow mark action")
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>