feat(hw-locks): hwlock_release() should return void

With the switch to the new mutex API, hwlock_release() cannot fail under
any circumstances.  To emphasize this, make it return void instead of
int (Previously it just always returned 0).

Signed-off-by: Rahix <rahix@rahix.de>

epicardium/modules/hw-lock.c

@@ -55,9 +55,8 @@ int hwlock_acquire(enum hwlock_periph p, TickType_t wait)
 	return 0;
 }
 
-int hwlock_release(enum hwlock_periph p)
+void hwlock_release(enum hwlock_periph p)
 {
 	assert(p < _HWLOCK_MAX);
 	mutex_unlock(&hwlock_mutex[p]);
-	return 0;
 }

epicardium/modules/modules.h

@@ -98,7 +98,7 @@ enum hwlock_periph {
 };
 
 int hwlock_acquire(enum hwlock_periph p, TickType_t wait);
-int hwlock_release(enum hwlock_periph p);
+void hwlock_release(enum hwlock_periph p);
 
 /* ---------- Display ------------------------------------------------------ */
 /* Forces an unlock of the display. Only to be used in Epicardium */