net: bnxt: Fix a uninitialized variable warning.

Fix the following compile warning:

drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c:49:5: warning: ‘nvm_param.dir_type’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  if (nvm_param.dir_type == BNXT_NVM_PORT_CFG)

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Acked-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>