[PATCH] uml: fix compile warning after consolidation patch

The header declaring this function wasn't included, so the function declaration
was totally bogus wrt. the proto - even if this wasn't going to fail at all.

It was so bad that the compile warning I got was "control reaches end of
non-void function", i.e. missing return. Actually, this has been there for ages,
the consolidation patch just added the warning which was needed to clean it up.
Nice. Really.

Cc: Allan Graves <allan.graves@gmail.com>
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/um/kernel/tt/process_kern.c

@@ -23,10 +23,11 @@
 #include "mem_user.h"
 #include "tlb.h"
 #include "mode.h"
+#include "mode_kern.h"
 #include "init.h"
 #include "tt.h"
 
-int switch_to_tt(void *prev, void *next, void *last)
+void switch_to_tt(void *prev, void *next)
 {
 	struct task_struct *from, *to, *prev_sched;
 	unsigned long flags;