features/gfid-access: error handling for entry creation

Proceed with setattr() only on a successfull entry creation.
Winding a setattr() using a freshlyOC initiated inode would
most likely fail in one translator or the other (e.g. DHT
expecting the layout information to be set in the inode
context), which is the case if the inode was not looked up.

Therefore, gfid-access handles failure entry creations and
passes the _correct_ errno back to the client instead of
continuing with setattr() call and probably returning back
incorrect errno. Also, filling up inode->gfid is required
as the new inode is not looked up and ->gfid would be
certainely required for inode operations.

Change-Id: Ie92f5647a89bf558c07710ab0400bce69d59fc31
BUG: 1111490
Signed-off-by: Venky Shankar <vshankar@redhat.com>
Reviewed-on: http://review.gluster.org/8260
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kotresh HR <khiremat@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>