pax: prevent possible buffer overflow

Or at least quiet down some static analyzers about it.

CID:	978835
MFC after:	1 week
Obtained from:	OpenBSD

bin/pax/pat_rep.c

@@ -878,7 +878,7 @@ rep_name(char *name, int *nlen, int prnt)
 	 * (the user already saw that substitution go by)
 	 */
 	pt = rephead;
-	(void)strcpy(buf1, name);
+	(void)strlcpy(buf1, name, sizeof(buf1));
 	inpt = buf1;
 	outpt = nname;
 	endpt = outpt + PAXPATHLEN;