Make vinum disk-related devices readable by group "operator" to match the configuration of any other disk-like devices.
Make vinum disk-related devices readable by group "operator" to match
the configuration of any other disk-like devices.

(This is the DEVFS-only part, so no need to MFC.)

PR:		bin/28294, bin/32588

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