kvm: x86: avoid warning about potential shift wrapping bug

cs.base is declared as a __u64 variable and vector is a u32 so this
causes a static checker warning.  The user indeed can set "sipi_vector"
to any u32 value in kvm_vcpu_ioctl_x86_set_vcpu_events(), but the
value should really have 8-bit precision only.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -880,7 +880,7 @@ int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu);
 
 void kvm_get_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg);
 int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector, int seg);
-void kvm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, unsigned int vector);
+void kvm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector);
 
 int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index,
 		    int reason, bool has_error_code, u32 error_code);

arch/x86/kvm/lapic.c

@@ -1954,7 +1954,7 @@ int kvm_lapic_enable_pv_eoi(struct kvm_vcpu *vcpu, u64 data)
 void kvm_apic_accept_events(struct kvm_vcpu *vcpu)
 {
 	struct kvm_lapic *apic = vcpu->arch.apic;
-	unsigned int sipi_vector;
+	u8 sipi_vector;
 	unsigned long pe;
 
 	if (!kvm_vcpu_has_lapic(vcpu) || !apic->pending_events)

arch/x86/kvm/x86.c

@@ -7033,7 +7033,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu)
 	kvm_x86_ops->vcpu_reset(vcpu);
 }
 
-void kvm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, unsigned int vector)
+void kvm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
 {
 	struct kvm_segment cs;