openrisc: pass correct arg to schedule_tail

schedule_tail() requires that the 'prev' task be passed as an argument
to it.  This arg is set in _switch, just before 'returning' to one of
the ret_* functions where schedule_tail is invoked.

Signed-off-by: Jonas Bonn <jonas@southpole.se>

arch/openrisc/kernel/process.c

@@ -165,7 +165,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 	 * the kernel stack.
 	 */
 	kregs->sp = top_of_kernel_stack;
-	kregs->gpr[3] = (unsigned long)current;	/* arg to schedule_tail */
 	kregs->gpr[10] = (unsigned long)task_thread_info(p);
 	kregs->gpr[9] = (unsigned long)ret_from_fork;