Move do_sleep() from helper.c --> util.c

This move makes it possible to share the code between the Finit daemon
and its client tools.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

util.h

@@ -27,6 +27,7 @@
 extern char *prognm;
 
 char *progname(char *arg0);
+void  do_sleep(unsigned int sec);
 
 #endif /* FINIT_UTIL_H_ */