Revert "Moved petname_used to decl.c"

This reverts commit 6272c37035.

src/decl.c

@@ -207,7 +207,6 @@ NEARDATA char dogname[PL_PSIZ] = DUMMY;
 NEARDATA char catname[PL_PSIZ] = DUMMY;
 NEARDATA char horsename[PL_PSIZ] = DUMMY;
 char preferred_pet; /* '\0', 'c', 'd', 'n' (none) */
-int petname_used = 0;
 /* monsters that went down/up together with @ */
 NEARDATA struct monst *mydogs = (struct monst *) 0;
 /* monsters that are moving to another dungeon level */
@@ -573,8 +572,7 @@ decl_early_init()
     ZEROARRAYN(dogname, PL_PSIZ);
     ZEROARRAYN(catname, PL_PSIZ);
     ZEROARRAYN(horsename, PL_PSIZ);
-    ZERO(preferred_pet);
-    ZERO(petname_used);
+    preferred_pet = 0;
     ZEROPTR(mydogs);
     ZEROPTR(migrating_mons);
 

src/dog.c

@@ -160,6 +160,7 @@ makedog()
     register struct obj *otmp;
     const char *petname;
     int pettype;
+    static int petname_used = 0;
 
     if (preferred_pet == 'n')
         return ((struct monst *) 0);