acpi_idle: add missing \n to printk

otherwise, these two lines print as one:

ACPI: acpi_idle yielding to intel_idle
ACPI: SSDT 3f5d8741 00203 (v02 PmRef  Cpu0Ist 00003000 INTL 20050624)
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/processor_driver.c

@@ -850,7 +850,7 @@ static int __init acpi_processor_init(void)
 		printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
 			acpi_idle_driver.name);
 	} else {
-		printk(KERN_DEBUG "ACPI: acpi_idle yielding to %s",
+		printk(KERN_DEBUG "ACPI: acpi_idle yielding to %s\n",
 			cpuidle_get_driver()->name);
 	}