libkern.h now internally uses the bzero() definition from sys/systm.h.

This is kinda important since the bzero symbol on i386 is not a function
but a function pointer..  If memset() tried to call it as though it were
a function, things would be less than satisfactory.  In reality though
this was not an actual problem and just caused compile warnings.

sys/sys/libkern.h

@@ -39,6 +39,7 @@
 
 #include <sys/cdefs.h>
 #include <sys/types.h>
+#include <sys/systm.h>
 
 /* BCD conversions. */
 extern u_char const	bcd2bin_data[];