Incorporate review comment

Author: kleisauke

system/lib/libc/musl/src/thread/pthread_detach.c

@@ -6,7 +6,7 @@ static int __pthread_detach(pthread_t t)
 #ifdef __EMSCRIPTEN__
 	// Attempt to detach a thread which does not point to a valid thread, or
 	// does not exist anymore.
-	if (!t || t->self != t) return ESRCH;
+	if (t->self != t) return ESRCH;
 #endif
 	/* If the cas fails, detach state is either already-detached
 	 * or exiting/exited, and pthread_join will trap or cleanup. */

system/lib/libc/musl/src/thread/pthread_join.c

@@ -16,7 +16,7 @@ static int __pthread_timedjoin_np(pthread_t t, void **res, const struct timespec
 #ifdef __EMSCRIPTEN__
 	// Attempt to join a thread which does not point to a valid thread, or
 	// does not exist anymore.
-	if (!t || t->self != t) return ESRCH;
+	if (t->self != t) return ESRCH;
 	// Thread is attempting to join to itself.  Already detached threads are
 	// handled below by returning EINVAL instead.
 	if (t->detach_state != DT_DETACHED && __pthread_self() == t) return EDEADLK;