examples: update do_reset prototype

One more place that was missed during the do_reset() unification.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

examples/api/libgenwrap.c

@@ -81,9 +81,10 @@ void __udelay(unsigned long usec)
 	ub_udelay(usec);
 }
 
-void do_reset (void)
+int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	ub_reset();
+	return 0;
 }
 
 void *malloc (size_t len)