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

diff --git a/util-linux/fsck_minix.c b/util-linux/fsck_minix.c
index 5f92f35..deb82f7 100644
--- a/util-linux/fsck_minix.c
+++ b/util-linux/fsck_minix.c
@@ -1249,7 +1249,7 @@
 void check2(void);
 #endif
 
-int fsck_minix_main(int argc, char **argv);
+int fsck_minix_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int fsck_minix_main(int argc, char **argv)
 {
 	struct termios tmp;