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/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index 36debc0..bbc3a4a 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -228,7 +228,7 @@
 #ifdef PTRACE_ARCH_PRCTL
         case PTRACE_ARCH_PRCTL:
                 /* XXX Calls ptrace on the host - needs some SMP thinking */
-                ret = arch_prctl_skas(child, data, (void *) addr);
+                ret = arch_prctl(child, data, (void *) addr);
                 break;
 #endif
 	default:
@@ -239,7 +239,7 @@
 	return ret;
 }
 
-void send_sigtrap(struct task_struct *tsk, union uml_pt_regs *regs,
+void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs,
 		  int error_code)
 {
 	struct siginfo info;
@@ -258,7 +258,7 @@
 /* XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and
  * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
  */
-void syscall_trace(union uml_pt_regs *regs, int entryexit)
+void syscall_trace(struct uml_pt_regs *regs, int entryexit)
 {
 	int is_singlestep = (current->ptrace & PT_DTRACE) && entryexit;
 	int tracesysgood;