net: bnxt: always return values from _bnxt_get_max_rings

Newly added code in the bnxt driver uses a couple of variables that
are never initialized when CONFIG_BNXT_SRIOV is not set, and gcc
correctly warns about that:

In file included from include/linux/list.h:8:0,
                 from include/linux/module.h:9,
                 from drivers/net/ethernet/broadcom/bnxt/bnxt.c:10:
drivers/net/ethernet/broadcom/bnxt/bnxt.c: In function 'bnxt_get_max_rings':
include/linux/kernel.h:794:26: warning: 'cp' may be used uninitialized in this function [-Wmaybe-uninitialized]
include/linux/kernel.h:794:26: warning: 'tx' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/net/ethernet/broadcom/bnxt/bnxt.c:5730:11: warning: 'rx' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/net/ethernet/broadcom/bnxt/bnxt.c:5736:6: note: 'rx' was declared here

This changes the condition so that we fall back to using the PF
data if VF is not available, and always initialize the variables
to something useful.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 6e6c5a57 ("bnxt_en: Modify bnxt_get_max_rings() to support shared or non shared rings.")
Acked-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>