KVM: x86: remove set but not used variable 'called'

Fixes gcc '-Wunused-but-set-variable' warning:

arch/x86/kvm/x86.c: In function kvm_make_scan_ioapic_request_mask:
arch/x86/kvm/x86.c:7911:7: warning: variable called set but not
used [-Wunused-but-set-variable]

It is not used since commit 7ee30bc1 ("KVM: x86: deliver KVM
IOAPIC scan request to target vCPUs")
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Fixes: 7ee30bc1 ("KVM: x86: deliver KVM IOAPIC scan request to target vCPUs")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.c

@@ -7900,11 +7900,10 @@ void kvm_make_scan_ioapic_request_mask(struct kvm *kvm,
 				       unsigned long *vcpu_bitmap)
 {
 	cpumask_var_t cpus;
-	bool called;
 
 	zalloc_cpumask_var(&cpus, GFP_ATOMIC);
 
-	called = kvm_make_vcpus_request_mask(kvm, KVM_REQ_SCAN_IOAPIC,
+	kvm_make_vcpus_request_mask(kvm, KVM_REQ_SCAN_IOAPIC,
 				    vcpu_bitmap, cpus);
 
 	free_cpumask_var(cpus);