perf tools: Simplify die() mechanism

This should die altogether, but for now lets remove a bit of this stuff,
as it is not used at all.

Cc: Adrian Hunter <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Wang Nan <[e-mail]>
Link: http://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/usage.c

···
 /* If we are in a dlopen()ed .so write to a global variable would segfault
  * (ugh), so keep things static. */
 static void (*usage_routine)(const char *err) NORETURN = usage_builtin;
-static void (*die_routine)(const char *err, va_list params) NORETURN = die_builtin;
 static void (*error_routine)(const char *err, va_list params) = error_builtin;
 static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
-
-void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN)
-{
-	die_routine = routine;
-}
 
 void set_warning_routine(void (*routine)(const char *err, va_list params))
 {
···
 	va_list params;
 
 	va_start(params, err);
-	die_routine(err, params);
+	die_builtin(err, params);
 	va_end(params);
 }
 

tools/perf/util/util.h

···
 
 #include "../../../include/linux/stringify.h"
 
-extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
 extern void set_warning_routine(void (*routine)(const char *err, va_list params));
 
 extern int prefixcmp(const char *str, const char *prefix);