tty: Disable default console blanking interval

BugLink: http://bugs.launchpad.net/bugs/869017

Console blanking is not enabling DPMS power saving (thereby negating any
power-saving benefit), and is simply turning the screen content blank. This
means that any crash output is invisible which is unhelpful on a server
(virtual or otherwise).

Furthermore, CRT burn in concerns should no longer govern the default case.
Affected users could always set consoleblank on the kernel command line.
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Adam Borowski <kilobyte@angband.pl>
Cc: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/vt/vt.c

@@ -181,7 +181,7 @@ int console_blanked;
 
 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
 static int vesa_off_interval;
-static int blankinterval = 10*60;
+static int blankinterval;
 core_param(consoleblank, blankinterval, int, 0444);
 
 static DECLARE_WORK(console_work, console_callback);