libxenguest: use bitmap_alloc

Use existing helper to allocate a bitmap.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
[ wei: rebase to staging ]
Signed-off-by: Wei Liu <wl@xen.org>

tools/libs/guest/xg_sr_save.c

@@ -809,7 +809,7 @@ static int setup(struct xc_sr_context *ctx)
         xch, dirty_bitmap, NRPAGES(bitmap_size(ctx->save.p2m_size)));
     ctx->save.batch_pfns = malloc(MAX_BATCH_SIZE *
                                   sizeof(*ctx->save.batch_pfns));
-    ctx->save.deferred_pages = calloc(1, bitmap_size(ctx->save.p2m_size));
+    ctx->save.deferred_pages = bitmap_alloc(ctx->save.p2m_size);
 
     if ( !ctx->save.batch_pfns || !dirty_bitmap || !ctx->save.deferred_pages )
     {