DRM: comment: halve -> half

Signed-off-by: Michael Witten <mfwitten@gmail.com>
DRM: comment: gdm_proc_lists -> drm_proc_lists

I assume `gdm_proc_lists' is a vestigial spelling.

Signed-off-by: Michael Witten <mfwitten@gmail.com>
DRM: cleanup: Remove unused `gamma_size'

The value of `gamma_size' is guaranteed to be zero when
the following `if' statement is reached:

  if (gamma_size == 0)
  	gamma_size = fb_helper->crtc_info[i].mode_set.crtc->gamma_size

Thus, it could be reduced to just the following:

  gamma_size = fb_helper->crtc_info[i].mode_set.crtc->gamma_size

However, `gamma_size' is never actually used anywhere. So, what's
the point? So, this commit removes it entirely from the function.

Signed-off-by: Michael Witten <mfwitten@gmail.com>