CVE-2025-37996 KVM: arm64: Fix uninitialized memcache pointer in user_mem_abort()

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix uninitialized memcache pointer in usermemabort Commit fce886a60207 "KVM: arm64: Plumb the pKVM MMU in KVM" made the initialization of the local memcache variable in usermemabort conditional, leaving a codepath whe...