net/bnxt: add null check for mark table
net/bnxt: add null check for mark table

During the port start, driver ignores mark table allocation failure.
This could cause a segfault due to NULL pointer dereference in
bnxt_set_mark_in_mbuf(). Fix this by checking the pointer validity
before accessing it.

Fixes: b87abb2e55cb ("net/bnxt: support marking packet")
Cc: stable@dpdk.org

Signed-off-by: Kalesh AP <818b6a3caba85cc3a76890be15484140b8e9f23b@broadcom.com>
Reviewed-by: Ajit Khaparde <01965fbd61169dc18f3fb5e13de7f67d298f8924@broadcom.com>
Reviewed-by: Somnath Kotur <b8220280eb86080d22ca0cb32db0b374b9a89cc6@broadcom.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk