IEEE 802.15.4: Add a bounds check

This avoids to have cp (current pointer on packet data) > ndo->ndo_snapend
in hex_and_ascii_print(), via ndo_default_print(), via ND_DEFAULTPRINT(),
in some cases.

Author: fxlb

print-802_15_4.c

@@ -2021,6 +2021,7 @@ ieee802_15_4_std_frames(netdissect_options *ndo,
 		if (len < 0) {
 			return 0;
 		}
+		ND_TCHECK_LEN(p, len);
 		p += len;
 		caplen -= len;
 	} else {