fix #K3656 - chest in pit

Using #loot while in a pit allows looting containers in that pit.
Using open and specifying the hero's spot when not in a pit allows
looting containers at hero's spot.  But using open while in a pit
complained about not being able to reach out of the pit before player
had a chance to give hero's spot at the place of interest, so did not
allow looting any container there.

Get a target spot before rejecting use of 'open' while in a pit.
The alternate prompt might be tty-centric.

include/extern.h

@@ -288,7 +288,8 @@ extern int getdir(const char *);
 extern void confdir(boolean);
 extern const char *directionname(int);
 extern int isok(coordxy, coordxy);
-extern int get_adjacent_loc(const char *, const char *, coordxy, coordxy, coord *);
+extern int get_adjacent_loc(const char *, const char *, coordxy, coordxy,
+                            coord *);
 extern const char *click_to_cmd(coordxy, coordxy, int);
 extern char get_count(const char *, char, long, cmdcount_nht *, unsigned);
 #ifdef HANGUPHANDLING