Fix test_pthread_cancel after last two commits raced. NFC (#19975)

See #19524 and #19963

Author: sbc100

test/pthread/test_pthread_cancel.cpp

@@ -15,8 +15,8 @@
 _Atomic long res = 43;
 static void cleanup_handler(void *arg)
 {
-  emscripten_outf("Called clean-up handler with arg %p", arg);
   long a = (long)arg;
+  emscripten_outf("Called clean-up handler with arg %ld", a);
   res -= a;
 }
 

test/pthread/test_pthread_cancel.out

@@ -1,4 +1,4 @@
 Canceling thread..
 Thread started!
 Called clean-up handler with arg 42
-After canceling, shared variable = 1.
+After canceling, shared variable = 1