LRO is incompatible and mutually exclusive with XDP. However, the needed
checks are only made when enabling XDP. If LRO is enabled when XDP is
already active, the command will succeed, and XDP will be skipped in the
data path, although still enabled.
This commit fixes the bug by checking the XDP status in
mlx5e_fix_features and disabling LRO if XDP is enabled.