usage.c: remove unused functions

This removes three functions that are not used anywhere.
Signed-off-by: NNanako Shiraishi <nanako3@lavabit.com>
Acked-by: NLars Hjemli <hjemli@gmail.com>
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>

git-compat-util.h

@@ -154,10 +154,7 @@ extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1,
 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 
-extern void set_usage_routine(void (*routine)(const char *err) NORETURN);
 extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
-extern void set_error_routine(void (*routine)(const char *err, va_list params));
-extern void set_warn_routine(void (*routine)(const char *warn, va_list params));
 
 extern int prefixcmp(const char *str, const char *prefix);
 extern time_t tm_to_time_t(const struct tm *tm);

usage.c

@@ -41,27 +41,11 @@ static void (*die_routine)(const char *err, va_list params) NORETURN = die_built
 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_usage_routine(void (*routine)(const char *err) NORETURN)
-{
-	usage_routine = routine;
-}
-
 void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN)
 {
 	die_routine = routine;
 }
 
-void set_error_routine(void (*routine)(const char *err, va_list params))
-{
-	error_routine = routine;
-}
-
-void set_warn_routine(void (*routine)(const char *warn, va_list params))
-{
-	warn_routine = routine;
-}
-
-
 void usage(const char *err)
 {
 	usage_routine(err);