We need to check devargs pointer before dereference it, if no devargs
specified then this driver just skips the device.
Fixes: 40ef35f4a5 ("net/ifc: detect if VDPA mode is specified")
Cc: stable@dpdk.org
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>