[PATCH] uml: idle thread needn't take access to init_mm

Comparing this code which is the actual body of the arch-independent
cpu_idle(), it is clear that it's unnecessary to set ->mm and ->active_mm;
beyond that, a kernel thread is not supposed to have ->mm != NULL, only
active_mm.

This showed up because I used the assumption (which is IMHO valid) that kernel
thread have their ->mm == NULL, and it failed for this thread.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/kernel/process_kern.c

@@ -185,10 +185,6 @@ void default_idle(void)
 {
 	CHOOSE_MODE(uml_idle_timer(), (void) 0);
 
-	atomic_inc(&init_mm.mm_count);
-	current->mm = &init_mm;
-	current->active_mm = &init_mm;
-
 	while(1){
 		/* endless idle loop with no priority at all */