KVM: replace vmalloc and memset with vzalloc

Let's use newly introduced vzalloc().

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index f2c2d84..13cefe2 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -640,13 +640,11 @@
 	/* Allocate if a slot is being created */
 #ifndef CONFIG_S390
 	if (npages && !new.rmap) {
-		new.rmap = vmalloc(npages * sizeof(*new.rmap));
+		new.rmap = vzalloc(npages * sizeof(*new.rmap));
 
 		if (!new.rmap)
 			goto out_free;
 
-		memset(new.rmap, 0, npages * sizeof(*new.rmap));
-
 		new.user_alloc = user_alloc;
 		new.userspace_addr = mem->userspace_addr;
 	}
@@ -669,14 +667,11 @@
 			     >> KVM_HPAGE_GFN_SHIFT(level));
 		lpages -= base_gfn >> KVM_HPAGE_GFN_SHIFT(level);
 
-		new.lpage_info[i] = vmalloc(lpages * sizeof(*new.lpage_info[i]));
+		new.lpage_info[i] = vzalloc(lpages * sizeof(*new.lpage_info[i]));
 
 		if (!new.lpage_info[i])
 			goto out_free;
 
-		memset(new.lpage_info[i], 0,
-		       lpages * sizeof(*new.lpage_info[i]));
-
 		if (base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
 			new.lpage_info[i][0].write_count = 1;
 		if ((base_gfn+npages) & (KVM_PAGES_PER_HPAGE(level) - 1))