bridge: vni: Remove dead code in group argument parsing

bridge: vni: Remove dead code in group argument parsing

is_addrtype_inet_not_multi(&daddr) may read an uninitialized "daddr". Even
if that is fixed, the error message that follows cannot be reached because
the situation would be caught by the previous test (group_present).
Therefore, remove this test on daddr.

Fixes: 45cd32f9f7d5 ("bridge: vxlan device vnifilter support")
Reviewed-by: Petr Machata <petrm@nvidia.com>
Tested-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>