Consolidate allocation of firmware buffers.  In the process, remove
  duplication of a workaround for an old symbol firmware bug, and fix a
  bug where we could retry the workaround, even if it already failed to
  help.
Signed-off-by: NDavid Gibson <hermes@gibson.dropbear.id.au>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>