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-x86_64/syscalls.c b/arch/um/sys-x86_64/syscalls.c
index d44398c..bbcab77 100644
--- a/arch/um/sys-x86_64/syscalls.c
+++ b/arch/um/sys-x86_64/syscalls.c
@@ -28,8 +28,7 @@
 	return err ? -EFAULT : 0;
 }
 
-long arch_prctl_skas(struct task_struct *task, int code,
-                     unsigned long __user *addr)
+long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
 {
         unsigned long *ptr = addr, tmp;
 	long ret;
@@ -91,7 +90,7 @@
 
 long sys_arch_prctl(int code, unsigned long addr)
 {
-	return arch_prctl_skas(current, code, (unsigned long __user *) addr);
+	return arch_prctl(current, code, (unsigned long __user *) addr);
 }
 
 long sys_clone(unsigned long clone_flags, unsigned long newsp,
@@ -108,10 +107,10 @@
 	return ret;
 }
 
-void arch_switch_to_skas(struct task_struct *from, struct task_struct *to)
+void arch_switch_to(struct task_struct *from, struct task_struct *to)
 {
         if((to->thread.arch.fs == 0) || (to->mm == NULL))
                 return;
 
-        arch_prctl_skas(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
+        arch_prctl(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
 }