Use macro unhideable_trap

src/bones.c

@@ -510,7 +510,7 @@ savebones(int how, time_t when, struct obj *corpse)
     }
     for (ttmp = g.ftrap; ttmp; ttmp = ttmp->ntrap) {
         ttmp->madeby_u = 0;
-        ttmp->tseen = (ttmp->ttyp == HOLE);
+        ttmp->tseen = unhideable_trap(ttmp->ttyp);
     }
     resetobjs(fobj, FALSE);
     resetobjs(g.level.buriedobjlist, FALSE);

src/trap.c

@@ -416,7 +416,7 @@ maketrap(coordxy x, coordxy y, int typ)
     ttmp->dst.dnum = ttmp->dst.dlevel = -1;
     ttmp->madeby_u = 0;
     ttmp->once = 0;
-    ttmp->tseen = (typ == HOLE); /* hide non-holes */
+    ttmp->tseen = unhideable_trap(typ);
     ttmp->ttyp = typ;
 
     switch (typ) {