KVM: arm64: pmu: Drop redundant check for non-NULL kvm_pmu_events

There is an allocated and valid struct kvm_pmu_events for each cpu on the
system via DEFINE_PER_CPU(). Hence there cannot be a NULL pointer accessed
via this_cpu_ptr() in the helper kvm_get_pmu_events(). Hence non-NULL check
for pmu in such places are redundant and can be dropped.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: kvmarm@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231012064617.897346-1-anshuman.khandual@arm.com

Author: Anshuman Khandual

arch/arm64/kvm/pmu.c

@@ -39,7 +39,7 @@ void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr)
 {
 	struct kvm_pmu_events *pmu = kvm_get_pmu_events();
 
-	if (!kvm_arm_support_pmu_v3() || !pmu || !kvm_pmu_switch_needed(attr))
+	if (!kvm_arm_support_pmu_v3() || !kvm_pmu_switch_needed(attr))
 		return;
 
 	if (!attr->exclude_host)
@@ -55,7 +55,7 @@ void kvm_clr_pmu_events(u32 clr)
 {
 	struct kvm_pmu_events *pmu = kvm_get_pmu_events();
 
-	if (!kvm_arm_support_pmu_v3() || !pmu)
+	if (!kvm_arm_support_pmu_v3())
 		return;
 
 	pmu->events_host &= ~clr;