xen-netback: reduce log spam

xen-netback: reduce log spam

Remove the "prepare for reconnect" pr_info in xenbus.c. It's largely
uninteresting and the states of the frontend and backend can easily be
observed by watching the (o)xenstored log.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 8e4ee59c1e75b74966476dcc3552c3b30d2768e7)
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
OraBug: 23268939