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/include/asm-um/ptrace-generic.h b/include/asm-um/ptrace-generic.h
index 99c87c5..c8b3e6b 100644
--- a/include/asm-um/ptrace-generic.h
+++ b/include/asm-um/ptrace-generic.h
@@ -12,7 +12,7 @@
 #include "sysdep/ptrace.h"
 
 struct pt_regs {
-	union uml_pt_regs regs;
+	struct uml_pt_regs regs;
 };
 
 #define EMPTY_REGS { .regs = EMPTY_UML_PT_REGS }
@@ -44,7 +44,7 @@
 
 extern void show_regs(struct pt_regs *regs);
 
-extern void send_sigtrap(struct task_struct *tsk, union uml_pt_regs *regs,
+extern void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs,
 			 int error_code);
 
 extern int arch_copy_tls(struct task_struct *new);