tests: kernel: increase stack buffer when code coverage enabled

increase stack buffer when code coverage enabled.

Fixes: #15794.

Signed-off-by: Wentong Wu <[email protected]>

Author: wentongwu

tests/kernel/mem_protect/userspace/src/main.c

@@ -903,7 +903,7 @@ static void domain_remove_part_context_switch(void)
  */
 
 #define NUM_STACKS	3
-#define STEST_STACKSIZE	1024
+#define STEST_STACKSIZE	(1024 + CONFIG_TEST_EXTRA_STACKSIZE)
 K_THREAD_STACK_DEFINE(stest_stack, STEST_STACKSIZE);
 K_THREAD_STACK_ARRAY_DEFINE(stest_stack_array, NUM_STACKS, STEST_STACKSIZE);