client: client3_3_readdir() - initialize ``local`` properly

A crash is observed in the following scenario on OSX

~~~
(gdb) p readdir_rsp_size
$1 = 1552
GLUSTERFS_RPC_REPLY_SIZE == 24
GLUSTERFS_RDMA_MAX_HEADER_SIZE == 228

((1552 + 24 + 228)) == 1804

GLUSTERFS_RDMA_INLINE_THRESHOLD == 2048

if ((readdir_rsp_size +
 GLUSTERFS_RPC_REPLY_SIZE +
 GLUSTERFS_RDMA_MAX_HEADER_SIZE) > GLUSTERFS_RDMA_INLINE_THRESHOLD)
  ----> False
~~~

``local`` is never initialized leads to NULL reference later.

This patch makes sure that local is initialized, correctly as its
done in client3_3_readdirp() call.

Change-Id: I46931fc96900b7740ae71536c954bb9deda5c879
BUG: 1132796
Signed-off-by: Harshavardhana <harsha@harshavardhana.net>
Reviewed-on: http://review.gluster.org/8511
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Tested-by: Raghavendra G <rgowdapp@redhat.com>