net/nfp: remove duplicated check when setting MAC address

net/nfp: remove duplicated check when setting MAC address

Reported by code analysis tool C++test (version 10.4):

> /build/dpdk-20.11/drivers/net/nfp/nfp_net.c
> 546   Conditions "(hw->ctrl &NFP_NET_CFG_CTRL_ENABLE) &&
        !! (hw->cap &NFP_NET_CFG_C" is always evaluated to false
> 547   Condition "! (hw->cap &NFP_NET_CFG_C" is always evaluated to false

The previous "if" checks exactly the same condition. Removal of duplicate
code.

Fixes: 2fe669f4bcd2 ("net/nfp: support MAC address change")
Cc: stable@dpdk.org
Signed-off-by: Maxime Gouin <maxime.gouin@6wind.com>
Reviewed-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Kevin Traynor <ktraynor@redhat.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>