mktrap() flags

This started out as a fix for a comment typo, then morphed a bit....

src/mklev.c

@@ -1724,7 +1724,7 @@ mktrap_victim(struct trap *ttmp)
 void
 mktrap(
     int num,              /* if non-zero, specific type of trap to make */
-    int mktrapflags,      /* MKTRAP_NOSPIDERWEB, WKTRAP_MAZEFLAG */
+    unsigned mktrapflags, /* MKTRAP_{SEEN,MAZEFLAG,NOSPIDERONWEB,NOVICTIM} */
     struct mkroom *croom, /* room to hold trap */
     coord *tm)            /* specific location for trap */
 {

src/sp_lev.c

@@ -1788,7 +1788,7 @@ create_trap(spltrap *t, struct mkroom *croom)
 {
     coordxy x = -1, y = -1;
     coord tm;
-    int mktrap_flags = MKTRAP_MAZEFLAG;
+    unsigned mktrap_flags = MKTRAP_MAZEFLAG;
 
     if (t->type == VIBRATING_SQUARE) {
         pick_vibrasquare_location();