cpuid: kvm_find_kvm_cpuid_features() should be declared 'static'

The lack a static declaration currently results in:

arch/x86/kvm/cpuid.c:128:26: warning: no previous prototype for function 'kvm_find_kvm_cpuid_features'

when compiling with "W=1".
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 760849b1 ("KVM: x86: Make sure KVM_CPUID_FEATURES really are KVM_CPUID_FEATURES")
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Message-Id: <20211115144131.5943-1-pdurrant@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/cpuid.c

@@ -125,7 +125,7 @@ static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu)
 	}
 }
 
-struct kvm_cpuid_entry2 *kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu)
+static struct kvm_cpuid_entry2 *kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu)
 {
 	u32 base = vcpu->arch.kvm_cpuid_base;