Add prototypes for rstat(3) and havedisk(3).
Add prototypes for rstat(3) and havedisk(3).

Requested by: kris, Emil Mikulic <emikulic@optushome.com.au>
MFC After: 1 day

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