HPET: Remove spurious HPET busy warning message.

On x86 systems with CONFIG_HPET_TIMER enabled, when
the HPET driver (drivers/char/hpet.c) is loaded,
an incorrect busy message is printed when the driver
initializes since the HPET has already been allocated
by the core timer code. Remove the warning message.

Signed-off-by: David John <davidjon@xenontk.org>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>