KVM: Drop unnecessary initialization of "npages" in hva_to_pfn_slow()

The variable is initialized but it is only used after its assignment.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Li kunyu <kunyu@nfschina.com>
Message-Id: <20220819022804.483914-1-kunyu@nfschina.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

virt/kvm/kvm_main.c

@@ -2518,7 +2518,7 @@ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
 {
 	unsigned int flags = FOLL_HWPOISON;
 	struct page *page;
-	int npages = 0;
+	int npages;
 
 	might_sleep();