Removing warnings by gcc -Wall -- cast ugly || to void.

Python/pystate.c

@@ -22,7 +22,7 @@ redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #ifdef WITH_THREAD
 #include "pythread.h"
 static PyThread_type_lock head_mutex = NULL; /* Protects interp->tstate_head */
-#define HEAD_INIT() (head_mutex || (head_mutex = PyThread_allocate_lock()))
+#define HEAD_INIT() (void)(head_mutex || (head_mutex = PyThread_allocate_lock()))
 #define HEAD_LOCK() PyThread_acquire_lock(head_mutex, WAIT_LOCK)
 #define HEAD_UNLOCK() PyThread_release_lock(head_mutex)
 #else