KVM: selftests: Drop now-redundant checks on PERF_CAPABILITIES writes

Now that vcpu_set_msr() verifies the expected "read what was wrote"
semantics of all durable MSRs, including PERF_CAPABILITIES, drop the
now-redundant manual checks in the VMX PMU caps test.

Link: https://lore.kernel.org/r/20230311004618.920745-14-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c

@@ -51,10 +51,7 @@ static void test_basic_perf_capabilities(union perf_capabilities host_cap)
 	struct kvm_vm *vm = vm_create_with_one_vcpu(&vcpu, NULL);
 
 	vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, 0);
-	ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), 0);
-
 	vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, host_cap.capabilities);
-	ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), host_cap.capabilities);
 
 	kvm_vm_free(vm);
 }
@@ -67,9 +64,6 @@ static void test_fungible_perf_capabilities(union perf_capabilities host_cap)
 	/* testcase 1, set capabilities when we have PDCM bit */
 	vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, PMU_CAP_FW_WRITES);
 
-	/* check capabilities can be retrieved with KVM_GET_MSR */
-	ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), PMU_CAP_FW_WRITES);
-
 	/* check whatever we write with KVM_SET_MSR is _not_ modified */
 	vcpu_run(vcpu);
 	ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), PMU_CAP_FW_WRITES);