arm64: KVM: use 'int' instead of 'u32' for variable 'target' in kvm_host.h.

'target' will be set to '-1' in kvm_arch_vcpu_init(), and it need check
'target' whether less than zero or not in kvm_vcpu_initialized().

So need define target as 'int' instead of 'u32', just like ARM has done.

The related warning:

  arch/arm64/kvm/../../../arch/arm/kvm/arm.c:497:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
Signed-off-by: Chen Gang <gang.chen@asianux.com>
[Marc: reformated the Subject line to fit the series]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

arch/arm64/include/asm/kvm_host.h

@@ -129,7 +129,7 @@ struct kvm_vcpu_arch {
 	struct kvm_mmu_memory_cache mmu_page_cache;
 
 	/* Target CPU and feature flags */
-	u32 target;
+	int target;
 	DECLARE_BITMAP(features, KVM_VCPU_MAX_FEATURES);
 
 	/* Detect first run of a vcpu */