vhost: change log levels in client mode

vhost: change log levels in client mode

Inability to connect to socket is a normal situation
in client mode because, in common case, server isn't
started yet. RTE_LOG_WARNING should be suitable for
the case of some unusual errors.
Message about reconnection is not an error at all.

Fixes: e623e0c6d8a5 ("vhost: add reconnect ability")
Cc: stable@dpdk.org
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>