CVE-2025-37860 sfc: fix NULL dereferences in ef100_process_design_param()

In the Linux kernel, the following vulnerability has been resolved: sfc: fix NULL dereferences in ef100processdesignparam Since cited commit, ef100probemain and hence also ef100checkdesignparams run before efx-netdev is created; consequently, we cannot netifsettsomaxsize or segs at this point. Mo...