Fix vault guard leaving monsters encased in stone

For some reason the vault guard fake corridor code checked
if the hero was outside the corridor before removing monsters.
But the vault end of the corridor usually gets sealed off
even while you're still in the corridor. This left monsters
stuck in solid rock.

doc/fixes37.0

@@ -76,6 +76,7 @@ when punished, involuntarily teleporting and landing within chain range of
 inventory cursing caused by "this water's no good" effect when drinking from
 	a fountain didn't update persistent inventory window
 fix priest created inside temple wall
+fix vault guard occasionally encasing monsters in stone
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository

src/vault.c

@@ -76,7 +76,7 @@ boolean forceshow;
         if ((mtmp = m_at(fcx, fcy)) != 0) {
             if (mtmp->isgd) {
                 return FALSE;
-            } else if (!in_fcorridor(grd, u.ux, u.uy)) {
+            } else {
                 if (mtmp->mtame)
                     yelp(mtmp);
                 if (!rloc(mtmp, TRUE))