Fix improper synchronization.
Fix improper synchronization.

Before accessing the `ip2client' map, one code path was acquiring
the wrong monitor, which lead to weird race conditions while it was
iterating on the map's entries.

Change-Id: I2b3ebd6f68950f276ebac0f4af858306d99e56a9

adityakishore/asynchbase,manolama/asynchbase,hhshuai/asynchbase,SteamShon/asynchbase,tsuna/asynchbase,nvoron23/asynchbase,mapr/asynchbase,Connexity/asynchbase,mapr/asynchbase,Connexity/asynchbase,OpenTSDB/asyncbigtable,hzy001/asynchbase,angushe/asynchbase,mway08/asynchbase,hhshuai/asynchbase,tempbottle/asynchbase,OpenTSDB/asynchbase,StumbleUponArchive/asynchbase,hzy001/asynchbase,manolama/asyncbigtable,Flipboard/asynchbase,adityakishore/asynchbase,tempbottle/asynchbase,StumbleUponArchive/asynchbase,Flipboard/asynchbase,SteamShon/asynchbase,yuzhu712/asynchbase,pythian/asynchbase,nvoron23/asynchbase,angushe/asynchbase,mway08/asynchbase,OpenTSDB/asynchbase,manolama/asynchbase,tsuna/asynchbase,yuzhu712/asynchbase