Fix occasional luac.cross crash (#2661)

A block of memory is accessed after having been freed. This was obscured by the fact that 'oBuf' is a pointer into the middle of the block 'dynamicTables', so when dynamicTables is freed, oBuf is pointing to freed memory. Occasionally, luac.cross would crash because of this.

app/uzlib/uzlib_deflate.c

@@ -568,7 +568,6 @@ int uzlib_compress (uchar **dest, uint *destLen, const uchar *src, uint srcLen)
     status = UZLIB_OK;
   }
 
-  FREE(dynamicTables);
   for (i=0; i<20;i++) DBG_PRINT("count %u = %u\n",i,debugCounts[i]);
 
   if (status == UZLIB_OK) {
@@ -581,5 +580,7 @@ int uzlib_compress (uchar **dest, uint *destLen, const uchar *src, uint srcLen)
     FREE(oBuf->buffer);
   }
 
+  FREE(dynamicTables);
+
   return status;
 }