Current console blanking code is broken.  It will first do a normal blank,
then start the VESA blank timer if vesa_off_interval != 0, and then proceed
to do the VESA blanking directly.  After the timer expires it will do the
VESA blanking a second time.  Also the vesa_powerdown() function doesn't
allow all VESA modes to be used.

With this patch the behaviour is:
1. Blank: vesa_off_interval != 0 -> Do normal blank
          vesa_off_interval == 0 -> Do VESA blank
2. Start the VESA blank timer if vesa_off_interval != 0 and
   vesa_power_mode != 0.

It also gets rid of the limiting vesa_powerdown() function.

Signed-off-by: Ville Syrjala <syrjala@sci.fi>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>