Lock the vnode while truncating the corefile.  This fixes a panic with softupdates dangling deps.
Lock the vnode while truncating the corefile.  This fixes a panic
with softupdates dangling deps.

Submitted by:	peter
MFC:		ASAP :)

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