NFSD: Correct the size calculation in fault_inject_write

If len == 0 we end up with size = (0 - 1), which could cause bad things
to happen in copy_from_user().

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
1 file changed