KVM: x86: Plumb "force_immediate_exit" into kvm_entry() tracepoint

Annotate the kvm_entry() tracepoint with "immediate exit" when KVM is
forcing a VM-Exit immediately after VM-Enter, e.g. when KVM wants to
inject an event but needs to first complete some other operation.
Knowing that KVM is (or isn't) forcing an exit is useful information when
debugging issues related to event injection.

Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20240110012705.506918-2-seanjc@google.com


Signed-off-by: Sean Christopherson <seanjc@google.com>