Set KVM_GET_VCPU_EVENTS and KVM_SET_VCPU_EVENTS parameter type to
`struct kvm_vcpu_events`. Events, plural.

Opportunistically fix few other typos.
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://lore.kernel.org/r/20230814222358.707877-4-mhal@rbox.coSigned-off-by: Sean Christopherson <seanjc@google.com>