Return controlled EINVAL when the fdescfs lookup routine is given string representing too large integer, instead of overflowing and possibly returning a random but valid vnode.
Return controlled EINVAL when the fdescfs lookup routine is given string
representing too large integer, instead of overflowing and possibly
returning a random but valid vnode.

Noted by:	Jilles Tjoelker <jilles stack nl>
MFC after:	3 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase