DHT/mkdir : Fill the stbuf from the subvols on which directory creation
was successful.

Problem: In case a mkdir sees EEXIST on a non-hashed subvol it reports
error to the application.

Change-Id: I44b2f32fc1069e609d788b6d25b9366b1460395c
BUG: 1114557
Signed-off-by: Susant Palai <spalai@redhat.com>
Reviewed-on: http://review.gluster.org/8203
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-by: Anders Blomdell <anders.blomdell@control.lth.se>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>