KVM: x86: Update the variable naming in kvm_x86_ops.sched_in()

Update the variable with name 'kvm' in kvm_x86_ops.sched_in() to 'vcpu' to
avoid confusions. Variable naming in KVM has a clear convention that 'kvm'
refers to pointer of type 'struct kvm *', while 'vcpu' refers to pointer of
type 'struct kvm_vcpu *'.

Fix this 9-year old naming issue for fun.

Signed-off-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20231017232610.4008690-1-mizhang@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: mzhang3579

arch/x86/include/asm/kvm_host.h

@@ -1701,7 +1701,7 @@ struct kvm_x86_ops {
 
 	void (*request_immediate_exit)(struct kvm_vcpu *vcpu);
 
-	void (*sched_in)(struct kvm_vcpu *kvm, int cpu);
+	void (*sched_in)(struct kvm_vcpu *vcpu, int cpu);
 
 	/*
 	 * Size of the CPU's dirty log buffer, i.e. VMX's PML buffer.  A zero