KVM: Remove unused kvm_make_cpus_request_mask() declaration

Commit 7ee30bc ("KVM: x86: deliver KVM IOAPIC scan request to target
vCPUs") declared but never implemented kvm_make_cpus_request_mask() as
kvm_make_vcpus_request_mask() already existed.

Note, KVM's APIs are painfully inconsistent, as the inclusive variant uses
"vcpus", whereas the exclusive/all variants use "cpus", which is likely
what led to the spurious declaration.  The "vcpus" terminology is more
correct, especially since the helpers will kick _physical_ CPUs by calling
kvm_kick_many_cpus().  But that's a cleanup for the future.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20230814140339.47732-1-yuehaibing@huawei.com
[sean: split to separate patch, call out inconsistent naming]
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: Yue Haibing

include/linux/kvm_host.h

@@ -190,8 +190,6 @@ bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
 bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req);
 bool kvm_make_all_cpus_request_except(struct kvm *kvm, unsigned int req,
 				      struct kvm_vcpu *except);
-bool kvm_make_cpus_request_mask(struct kvm *kvm, unsigned int req,
-				unsigned long *vcpu_bitmap);
 
 #define KVM_USERSPACE_IRQ_SOURCE_ID		0
 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID	1