CVE-2025-37912 ice: Check VF VSI Pointer Value in ice_vc_add_fdir_fltr()

In the Linux kernel, the following vulnerability has been resolved: ice: Check VF VSI Pointer Value in icevcaddfdirfltr As mentioned in the commit baeb705fd6a7 "ice: always check VF VSI pointer values", we need to perform a null pointer check on the return value of icegetvfvsi before using it...