Move _bsnmptools_debug extern from bsnmpmap.c to bsnmptools.h

It was used in bsnmpmap.c but was stored in bsnmptools.c; moving the extern
to the header allows us to cover all of our bases for the variable, and allows
_bsnmptools_debug to be used in the future elsewhere -- not just bsnmpmap.c.

MFC after: 3 weeks
Sponsored by: EMC / Isilon Storage Division

usr.sbin/bsnmpd/tools/libbsnmptools/bsnmpmap.c

@@ -47,7 +47,6 @@
 #include "bsnmptc.h"
 #include "bsnmptools.h"
 
-extern int _bsnmptools_debug;
 #define	DEBUG	if (_bsnmptools_debug) fprintf
 
 /* Allocate memory and initialize list. */

usr.sbin/bsnmpd/tools/libbsnmptools/bsnmptools.h

@@ -231,7 +231,7 @@ extern struct snmp_toolinfo snmptool;
 #define	SET_NONREP(ctx, i)	(((ctx)->flags |= (((i) & 0xff) << 24)))
 #define	GET_NONREP(ctx)		(((ctx)->flags & NONREP_BITS) >> 24)
 
-
+extern int _bsnmptools_debug;
 extern const struct asn_oid IsoOrgDod_OID;
 
 int snmptool_init(struct snmp_toolinfo *);