Removed duplicated words in in comments and docs.
diff --git a/Python/thread.c b/Python/thread.c
index dd333e8..c54670d 100644
--- a/Python/thread.c
+++ b/Python/thread.c
@@ -271,7 +271,7 @@
         if (p->id == id && p->key == key)
             goto Done;
         /* Sanity check.  These states should never happen but if
-         * they do we must abort.  Otherwise we'll end up spinning in
+         * they do we must abort.  Otherwise we'll end up spinning
          * in a tight loop with the lock held.  A similar check is done
          * in pystate.c tstate_delete_common().  */
         if (p == prev_p)