net/af_xdp: remove useless assignment
net/af_xdp: remove useless assignment

Assignment of function parameter 'umem' removed.

Fixes: f0ce7af0e182 ("net/af_xdp: remove resources when port is closed")
Cc: stable@dpdk.org

Signed-off-by: Ferruh Yigit <ba8734c3c506d2e3557bd4ac8fdaccd25bdb9aa7@intel.com>
Reviewed-by: David Marchand <f28529695cfa9e3e1eb84e7072aa626af4abb18e@redhat.com>

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