socket: Prevent extra logging in socket_rwv

Problem:
If the socket is not even connected socket_rwv fails
and the error log comes every 3 seconds for every
re-connect.

Fix:
Prevent this error log if the socket is not even
connected.

Change-Id: I963f1345c4b6779dd5491948f7f5c4357a507b67
BUG: 963088
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/5008
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>