drm - Hack around a drm_setmaster issue

drm - Hack around a drm_setmaster issue

* Currently the first-open automatically sets master.  A later attempt
  to issue the drm_set_master ioctl then fails because it is already set.

  It is unclear whether linux automatically sets master on first open
  or not, and quickly hacking that to not results in unhappiness, so...

* For now, just allow the master to be overridden by the ioctl.  And
  throw in some additional kprintf()s to help with debugging.

* Fixes the setDrmMaster error message on X startup and allows X
  to start.