Documentation: networking: switchdev: separate bulleted items with new line

It looks like "make htmldocs" produces this warning:
Documentation/networking/switchdev.rst:482: WARNING: Unexpected indentation.

Fixes: 0f22ad45f4 ("Documentation: networking: switchdev: clarify device driver behavior")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/switchdev.rst

@@ -479,6 +479,7 @@ is not possible.
   be added to a second bridge, which includes other switch ports or software
   interfaces. Some approaches to ensure that the forwarding domain for traffic
   belonging to the VLAN upper interfaces are managed properly:
+
     * If forwarding destinations can be managed per VLAN, the hardware could be
       configured to map all traffic, except the packets tagged with a VID
       belonging to a VLAN upper interface, to an internal VID corresponding to