Pass 'curthread' into VFS_STATFS() from acctwatch(), rather than passing NULL.  The NFS client expects that a thread will always be present for a VOP so that it can check for signal conditions, and will dereference a NULL pointer if one isn't present.
Pass 'curthread' into VFS_STATFS() from acctwatch(), rather than passing
NULL.  The NFS client expects that a thread will always be present for a
VOP so that it can check for signal conditions, and will dereference a
NULL pointer if one isn't present.

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