Fix error return in create.  (See comment in xdr for createtype4 at end of
rfc3530.)

From: Andy Adamson <andros@citi.umich.edu>
From: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>