um: Remove signal translation and exec_domain

As execution domain support is gone we can remove
signal translation from the signal code and remove
exec_domain from thread_info.
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/include/asm/thread_info.h

@@ -14,7 +14,6 @@
 
 struct thread_info {
 	struct task_struct	*task;		/* main task structure */
-	struct exec_domain	*exec_domain;	/* execution domain */
 	unsigned long		flags;		/* low level flags */
 	__u32			cpu;		/* current CPU */
 	int			preempt_count;  /* 0 => preemptable,
@@ -28,7 +27,6 @@ struct thread_info {
 #define INIT_THREAD_INFO(tsk)			\
 {						\
 	.task =		&tsk,			\
-	.exec_domain =	&default_exec_domain,	\
 	.flags =		0,		\
 	.cpu =		0,			\
 	.preempt_count = INIT_PREEMPT_COUNT,	\

arch/x86/um/signal.c

@@ -549,13 +549,6 @@ int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
 	if (err)
 		return err;
 
-	/* Set up registers for signal handler */
-	{
-		struct exec_domain *ed = current_thread_info()->exec_domain;
-		if (unlikely(ed && ed->signal_invmap && sig < 32))
-			sig = ed->signal_invmap[sig];
-	}
-
 	PT_REGS_SP(regs) = (unsigned long) frame;
 	PT_REGS_DI(regs) = sig;
 	/* In case the signal handler was declared without prototypes */