kill off sysfs()

libc/sysdeps/linux/common/sysfs.c

@@ -7,5 +7,10 @@
  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
  */
 
+/* libc isn't really supposed to export this */
+#if 0
+
 #include "syscalls.h"
 _syscall3(int, sysfs, int, option, unsigned int, index, char, addr);
+
+#endif