fix issue #843 - vampire revival sequencing

Reported by Umbire:
|You kill SpaceMannSpiff!  SpaceMannSpiff puts on a dwarvish cloak.
|SpaceMannSpiff puts on a dwarvish iron helm.
|The seemingly dead SpaceMannSpiff suddenly transforms and rises as
| a Vampire.

This was tough to reproduce but I finally managed it.  The issue
text mentions that it was fixed by copperwater in xNetHack with
commit 8c4af50f0aa3e72522f3eb98df039ff25c2a1ea0 to the repository
for that variant.  My attempt to cherry-pick that failed--I'm not
even sure whether it should have been expected to work--and some of
the code has been impinged upon by changes, so I ended up applying
the contents of that commit manually.

The commit changes how/when monsters put on new armor rather than
anything directly related to vampires.  Circumstances similar to
the example above now yield:
|You kill SpaceMannSpiff!
|The seemingly dead SpaceMannSpiff suddenly transforms and rises as
| a Vampire.
on one turn, then on the next turn the revived vampire produces:
|SpaceMannSpiff puts on a dwarvish cloak.

My test case only had one item of interest; I assume that the second
item of armor gets worn on a subsequent turn rather than at the same
time as the first one.

Fixes #843

src/zap.c

@@ -178,7 +178,8 @@ bhitm(struct monst *mtmp, struct obj *otmp)
             if (disguised_mimic)
                 seemimic(mtmp);
             mon_adjust_speed(mtmp, -1, otmp);
-            m_dowear(mtmp, FALSE); /* might want speed boots */
+            check_gear_next_turn(mtmp); /* might want speed boots */
+
             if (engulfing_u(mtmp) && is_whirly(mtmp->data)) {
                 You("disrupt %s!", mon_nam(mtmp));
                 pline("A huge hole opens up...");
@@ -191,7 +192,7 @@ bhitm(struct monst *mtmp, struct obj *otmp)
             if (disguised_mimic)
                 seemimic(mtmp);
             mon_adjust_speed(mtmp, 1, otmp);
-            m_dowear(mtmp, FALSE); /* might want speed boots */
+            check_gear_next_turn(mtmp); /* might want speed boots */
         }
         if (mtmp->mtame)
             helpful_gesture = TRUE;