fix #K3895 - 'o' at own spot during pass-walls

If standing at the location of a closed door while having Passes_walls
ability, attemping to open that door with 'o' reported "you don't find
anything here to loot".

Using 'o' to loot for direction ./>/< is intentional but it ignored
the possibility of there also being a closed door present.  When the
latter applies, only switch from open to loot for direction '>' so
that '.' (and '<') will open the door.  Doesn't matter for creatures
that can ooze under a closed door--trying to use 'o' gets rejected for
them because they lack hands.

Also allow hero in Passes_walls form to use 'c' when at open door spot.
(For creatures that ooze under doors, 'c' is rejected just like 'o'.)

Unrelated:  fix a typo in a recently added comment.

src/trap.c

@@ -6162,7 +6162,7 @@ lava_effects(void)
         iflags.in_lava_effects--;
 
         /*
-         * 3.7: this used to be uncondtional "back on solid <surface>"
+         * 3.7: this used to be unconditional "back on solid <surface>"
          * but surface() could return a lot of things where that ends up
          * sounding silly.  Deal with water, ignore furniture; assume
          * surface types 'air' and 'cloud' won't be present on same level