KVM: VMX: Heed the 'msr' argument in msr_write_intercepted()

KVM: VMX: Heed the 'msr' argument in msr_write_intercepted()

Regardless of the 'msr' argument passed to the VMX version of
msr_write_intercepted(), the function always checks to see if a
specific MSR (IA32_SPEC_CTRL) is intercepted for write.  This behavior
seems unintentional and unexpected.

Modify the function so that it checks to see if the provided 'msr'
index is intercepted for write.

Fixes: 67f4b9969c30 ("KVM: nVMX: Handle dynamic MSR intercept toggling")
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220810213050.2655000-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>