libbb: mark scripted_main() as externally visible

Building with individual binaries enabled fails when embedded
script applets are included:

   /tmp/ccIvMFZg.o: In function `main':
   applet.c:(.text.main+0x20): undefined reference to `scripted_main'

Mark scripted_main() as externally visible.

Reported-by: Yann E. MORIN <yann.morin.1998@free.fr>
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

include/libbb.h

@@ -1347,7 +1347,7 @@ void bb_logenv_override(void) FAST_FUNC;
 
 /* Embedded script support */
 char *get_script_content(unsigned n) FAST_FUNC;
-int scripted_main(int argc, char** argv);
+int scripted_main(int argc, char** argv) MAIN_EXTERNALLY_VISIBLE;
 
 /* Applets which are useful from another applets */
 int bb_cat(char** argv) FAST_FUNC;

libbb/appletlib.c

@@ -770,6 +770,7 @@ static int find_script_by_name(const char *name)
 	return -1;
 }
 
+int scripted_main(int argc UNUSED_PARAM, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int scripted_main(int argc UNUSED_PARAM, char **argv)
 {
 	int script = find_script_by_name(applet_name);