NFS: Repair whitespace damage in NFS PROC macro

Clean up.

When I was making other changes in this area, checkscript.pl
complained about the use of leading blanks in the PROC macros in the
xdr files.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>