Clean up useless getnatp() in conv(), nav_map(), tele()

Spotted by the Clang Static Analyzer.

src/lib/commands/conv.c

@@ -52,8 +52,6 @@ conv(void)
     struct lndstr land;
     struct nstr_item ni;
 
-
-    natp = getnatp(player->cnum);
     if (!snxtsct(&nstr, player->argp[1]))
 	return RET_SYN;
     uwtoconvert = onearg(player->argp[2], "Number to convert: ");

src/lib/commands/navi.c

@@ -278,7 +278,6 @@ nav_map(int x, int y, int show_designations)
 {
     char *ptr;
     struct nstr_sect ns;
-    struct natstr *np;
     struct sctstr sect;
     int i;
     /* Note this is not re-entrant anyway, so we keep the buffers
@@ -305,7 +304,6 @@ nav_map(int x, int y, int show_designations)
 	return RET_FAIL;
     }
     snxtsct_dist(&ns, x, y, 1);
-    np = getnatp(player->cnum);
     blankfill(wmapbuf, &ns.range, 1);
     while (nxtsct(&ns, &sect)) {
 	ptr = &wmap[ns.dy][ns.dx];

src/lib/commands/tele.c

@@ -46,7 +46,6 @@ tele(void)
     char buf[MAXTELSIZE + 1];	/* UTF-8 */
     int n;
 
-    natp = getnatp(player->cnum);
     if (*player->argp[0] == 'a') {
 	if (getele("everybody", buf) <= 0) {
 	    pr("Announcement aborted\n");