Now that SVM and VMX both probe MSRs before "defining" user return slots
for them, consolidate the code for probe+define into common x86 and
eliminate the odd behavior of having the vendor code define the slot for
a given MSR.
Signed-off-by: NSean Christopherson <seanjc@google.com>
Message-Id: <20210504171734.1434054-14-seanjc@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>