Use btest_exit in test_memory_growth_during_startup. NFC (#24894)

Author: sbc100

test/test_browser.py

@@ -3706,7 +3706,7 @@ def test_dylink_pthread_many(self):
   @no_4gb('uses INITIAL_MEMORY')
   def test_memory_growth_during_startup(self):
     create_file('data.dat', 'X' * (30 * 1024 * 1024))
-    self.btest('browser_test_hello_world.c', '0', cflags=['-sASSERTIONS', '-sALLOW_MEMORY_GROWTH', '-sINITIAL_MEMORY=16MB', '-sSTACK_SIZE=16384', '--preload-file', 'data.dat'])
+    self.btest_exit('browser_test_hello_world.c', cflags=['-sASSERTIONS', '-sALLOW_MEMORY_GROWTH', '-sINITIAL_MEMORY=16MB', '-sSTACK_SIZE=16384', '--preload-file', 'data.dat'])
 
   # pthreads tests