app/testpmd: fix build without drivers
app/testpmd: fix build without drivers

When ixgbe and bnxt are disabled, compilation was failing:

app/test-pmd/cmdline.c:9396:11: error:
	variable 'vf_rxmode' set but not used

Fixes: 4cfe399f6550 ("net/bnxt: support to set VF rxmode")
Cc: stable@dpdk.org

Signed-off-by: Thomas Monjalon <5f50a84c1fa3bcff146405017f36aec1a10a9e38@monjalon.net>
Acked-by: Bruce Richardson <66b9e8e8fbd5e9f41f91b0af050876182ce9d0e4@intel.com>
Acked-by: Ajit Khaparde <01965fbd61169dc18f3fb5e13de7f67d298f8924@broadcom.com>

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