This patch decrements maxcnt by the appropriate
number of bytes during parsing and checks to see
if there is data remaining. If not, it just returns
from nfsrv_flexlayouterr() without further processing.
This prevents the tl pointer from running off the end
of the error data pointed at by layp, if there are
flaws in the data.
Reported by: rtm@lcs.mit.edu
Tested by: rtm@lcs.mit.edu
PR: 260293
MFC after: 2 weeks
c302f889e2