Robert P. Day removed 8 gazillion occurrences of "extern" on function
definitions.  (That should only be on prototypes.)
diff --git a/procps/free.c b/procps/free.c
index 4fb047d..b4163f1 100644
--- a/procps/free.c
+++ b/procps/free.c
@@ -27,7 +27,7 @@
 #include <stdlib.h>
 #include "busybox.h"
 
-extern int free_main(int argc, char **argv)
+int free_main(int argc, char **argv)
 {
 	struct sysinfo info;
 	sysinfo(&info);