We will use this later in the series to eliminate the need for a function
call.

[ Steven Rostedt: added task_is_current function ]
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>