KVM: SEV: Drop a redundant setting of sev->asid during initialization

Remove a fully redundant write to sev->asid during SEV/SEV-ES guest
initialization.  The ASID is set a few lines earlier prior to the call to
sev_platform_init(), which doesn't take "sev" as a param, i.e. can't
muck with the ASID barring some truly magical behind-the-scenes code.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211109215101.2211373-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>