IPVS: precedence bug in ip_vs_sync_switch_mode()

'!' has higher precedence than '&'.  IP_VS_STATE_MASTER is 0x1 so
the original code is equivelent to if (!ipvs->sync_state) ...

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: Simon Horman <horms@verge.net.au>