warning fix

The new code provoked several warnings; this fixes one of them.
Moving the declaration of 'rolecount' would have been sufficient,
but I've gone another way.

src/pray.c

@@ -2095,15 +2095,13 @@ aligntyp alignment;
     if (!Hallucination)
         return align_gname(alignment);
 
-    /* Count the roles, so that we can pick one at random. */
-    int rolecount = 0;
-    while (roles[rolecount].filecode)
-        rolecount++;
-
-    /* The priest may not have initialized god names. If this is the
-       case, and we roll priest, we need to try again. */
+    /* Some roles (Priest) don't have a pantheon unless we're playing as
+       that role, so keep trying until we get a role which does have one.
+       [If playing a Priest, the current pantheon will be twice as likely
+       to get picked as any of the others.  That's not significant enough
+       to bother dealing with.] */
     do
-        which = rn2_on_display_rng(rolecount);
+        which = randrole(TRUE);
     while (!roles[which].lgod);
 
     switch (rn2_on_display_rng(9)) {