KVM: Don't call get_user_pages(.force = 1)

This is esoteric and only needed to break COW on MAP_SHARED mappings.  Since
KVM no longer does these sorts of mappings, breaking COW on them is no longer
necessary.
Signed-off-by: Avi Kivity <avi@qumranet.com>

virt/kvm/kvm_main.c

@@ -734,7 +734,7 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
 		return page_to_pfn(bad_page);
 	}
 
-	npages = get_user_pages(current, current->mm, addr, 1, 1, 1, page,
+	npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
 				NULL);
 
 	if (unlikely(npages != 1)) {