[PATCH] uml: Remove bogus __NR_sigreturn check

Before Bodo's signal fixes and my signal delivery rework, it was possible for
a process to execute UML code by running the default signal restorer.  This
is no longer possible, so this check can be removed from the sanity test for
UML accidentally tracing itself.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/kernel/tt/syscall_user.c

@@ -57,8 +57,7 @@ void do_syscall(void *task, int pid, int local_using_sysemu)
 
 	UPT_SYSCALL_NR(TASK_REGS(task)) = PT_SYSCALL_NR(proc_regs);
 
-	if((syscall != __NR_sigreturn) &&
-	   ((unsigned long *) PT_IP(proc_regs) >= &_stext) && 
+	if(((unsigned long *) PT_IP(proc_regs) >= &_stext) &&
 	   ((unsigned long *) PT_IP(proc_regs) <= &_etext))
 		tracer_panic("I'm tracing myself and I can't get out");