add -fvisibility=hidden to CC flags, mark XXX_main functions
EXTERNALLY_VISIBLE. 5% size reduction of libbusybox.so

diff --git a/console-tools/setkeycodes.c b/console-tools/setkeycodes.c
index 3de5f98..ba3d2e4 100644
--- a/console-tools/setkeycodes.c
+++ b/console-tools/setkeycodes.c
@@ -20,8 +20,8 @@
 	KDSETKEYCODE = 0x4B4D  /* write kernel keycode table entry */
 };
 
-int setkeycodes_main(int argc, char** argv);
-int setkeycodes_main(int argc, char** argv)
+int setkeycodes_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int setkeycodes_main(int argc, char **argv)
 {
 	int fd, sc;
 	struct kbkeycode a;