Currently the check to see if a page is allocated is incorrect
and is checking if the pointer page is null, not *page as
intended.  Fix this.
Addresses-Coverity: ("Dereference before null check")
Fixes: f5cedc84a30d ("gve: Add transmit and receive support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
                   enum dma_data_direction dir)
 {
        *page = alloc_page(GFP_KERNEL);
-       if (!page)
+       if (!*page)
                return -ENOMEM;
        *dma = dma_map_page(dev, *page, 0, PAGE_SIZE, dir);
        if (dma_mapping_error(dev, *dma)) {