KVM: x86/pmu: Remove manual clearing of fields in kvm_pmu_init()

Remove code that unnecessarily clears event_count and need_cleanup in
kvm_pmu_init(), the entire kvm_pmu is zeroed just a few lines earlier.
Vendor code doesn't set event_count or need_cleanup during .init(), and
if either VMX or SVM did set those fields it would be a flagrant bug.

Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20231103230541.352265-5-seanjc@google.com


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