libxl: fix matching of generic virtio device

The strings won't be an exact match, as we are only looking to match the
prefix here, i.e. "virtio,device". This is already done properly in
libxl_virtio.c file, lets do the same here too.

Fixes: 43ba5202e2 ("libxl: add support for generic virtio device")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>

tools/libs/light/libxl_arm.c

@@ -1033,10 +1033,14 @@ static int make_virtio_mmio_node_device(libxl__gc *gc, void *fdt, uint64_t base,
     } else if (!strcmp(type, VIRTIO_DEVICE_TYPE_GPIO)) {
         res = make_virtio_mmio_node_gpio(gc, fdt);
         if (res) return res;
-    } else if (strcmp(type, VIRTIO_DEVICE_TYPE_GENERIC)) {
-        /* Doesn't match generic virtio device */
-        LOG(ERROR, "Invalid type for virtio device: %s", type);
-        return -EINVAL;
+    } else {
+        int len = sizeof(VIRTIO_DEVICE_TYPE_GENERIC) - 1;
+
+        if (strncmp(type, VIRTIO_DEVICE_TYPE_GENERIC, len)) {
+            /* Doesn't match generic virtio device */
+            LOG(ERROR, "Invalid type for virtio device: %s", type);
+            return -EINVAL;
+        }
     }
 
     return fdt_end_node(fdt);