nfsd warning fix

fs/nfsd/nfsctl.c: In function 'write_filehandle':
fs/nfsd/nfsctl.c:301: warning: 'maxsize' may be used uninitialized in this function

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Acked-by:  Neil Brown <neilb@suse.de>