net/bnxt: fix crash during Tx

net/bnxt: fix crash during Tx

When TRUFLOW is not enabled ulp_ctx is not allocated.
In non-vector Tx datapath we are accessing this invalid pointer
resulting in a segfault. Check if TRUFLOW is enabled before
accessing ulp_ctx to avoid this.

Fixes: 1e46b3962620 ("net/bnxt: fill cfa action in Tx descriptor")
Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Venkat Duvvuru <venkatkumar.duvvuru@broadcom.com>