bnxt_en: Fix population of flow_type in bnxt_hwrm_cfa_flow_alloc()

flow_type in HWRM_FLOW_ALLOC is not being populated correctly due to
incorrect passing of pointer and size of l3_mask argument of is_wildcard().
Fixed this.

Fixes: db1d36a2

 ("bnxt_en: add TC flower offload flow_alloc/free FW cmds")
Signed-off-by: Sunil Challa <sunilkumar.challa@broadcom.com>
Reviewed-by: Sathya Perla <sathya.perla@broadcom.com>
Reviewed-by: Venkat Duvvuru <venkatkumar.duvvuru@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>