Search bdevsw[] instead of the half-baked builtin table of devices in the RB_ASKNAME case.  I had thought that I made this change in rev.1.18, but rev.1.18 only affects obscure subcases of the RB_DFLTROOT case (subcases where the compiled in default root is not found in bdevsw[] -- then the root device is set to the first device in the half-baked table that is also in bdevsw[]).
Search bdevsw[] instead of the half-baked builtin table of devices
in the RB_ASKNAME case.  I had thought that I made this change in
rev.1.18, but rev.1.18 only affects obscure subcases of the
RB_DFLTROOT case (subcases where the compiled in default root is
not found in bdevsw[] -- then the root device is set to the first
device in the half-baked table that is also in bdevsw[]).

Removed yet more vestiges of config-time swap configuration.

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