9p: Optimize TCREATE by eliminating a redundant fid clone.

This patch removes a redundant fid clone on the directory fid and hence
reduces a server transaction while creating new filesystem object.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>