uml: remove code made redundant by CHOOSE_MODE removal

This patch makes a number of simplifications enabled by the removal of
CHOOSE_MODE.  There were lots of functions that looked like

	int foo(args){
		foo_skas(args);
	}

The bodies of foo_skas are now folded into foo, and their declarations (and
sometimes entire header files) are deleted.

In addition, the union uml_pt_regs, which was a union between the tt and skas
register formats, is now a struct, with the tt-mode arm of the union being
removed.

It turns out that usr2_handler was unused, so it is gone.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/sys-i386/ptrace.c b/arch/um/sys-i386/ptrace.c
index 7792365..dcf0c6b 100644
--- a/arch/um/sys-i386/ptrace.c
+++ b/arch/um/sys-i386/ptrace.c
@@ -14,16 +14,18 @@
 #include "sysdep/sigcontext.h"
 #include "sysdep/sc.h"
 
-void arch_switch_to_skas(struct task_struct *from, struct task_struct *to)
+extern int arch_switch_tls(struct task_struct *from, struct task_struct *to);
+
+void arch_switch_to(struct task_struct *from, struct task_struct *to)
 {
-	int err = arch_switch_tls_skas(from, to);
+	int err = arch_switch_tls(from, to);
 	if (!err)
 		return;
 
 	if (err != -EINVAL)
-		printk(KERN_WARNING "arch_switch_tls_skas failed, errno %d, not EINVAL\n", -err);
+		printk(KERN_WARNING "arch_switch_tls failed, errno %d, not EINVAL\n", -err);
 	else
-		printk(KERN_WARNING "arch_switch_tls_skas failed, errno = EINVAL\n");
+		printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n");
 }
 
 int is_syscall(unsigned long addr)