[PATCH] adjust clock for lost ticks

A large number of lost ticks can cause an overadjustment of the clock.  To
compensate for this we look at the current error and the larger the error
already is the more careful we are at adjusting the error.  As small extra
fix reset the error when the clock is set.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Acked-by: john stultz <johnstul@us.ibm.com>
Cc: Uwe Bugla <uwe.bugla@gmx.de>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>