syscall: rename Z_OOPS -> K_OOPS

Rename internal API to not use z_/Z_.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
diff --git a/kernel/stack.c b/kernel/stack.c
index 72db870..6ada39c 100644
--- a/kernel/stack.c
+++ b/kernel/stack.c
@@ -64,8 +64,8 @@
 static inline int32_t z_vrfy_k_stack_alloc_init(struct k_stack *stack,
 					      uint32_t num_entries)
 {
-	Z_OOPS(K_SYSCALL_OBJ_NEVER_INIT(stack, K_OBJ_STACK));
-	Z_OOPS(K_SYSCALL_VERIFY(num_entries > 0));
+	K_OOPS(K_SYSCALL_OBJ_NEVER_INIT(stack, K_OBJ_STACK));
+	K_OOPS(K_SYSCALL_VERIFY(num_entries > 0));
 	return z_impl_k_stack_alloc_init(stack, num_entries);
 }
 #include <syscalls/k_stack_alloc_init_mrsh.c>
@@ -132,7 +132,7 @@
 #ifdef CONFIG_USERSPACE
 static inline int z_vrfy_k_stack_push(struct k_stack *stack, stack_data_t data)
 {
-	Z_OOPS(K_SYSCALL_OBJ(stack, K_OBJ_STACK));
+	K_OOPS(K_SYSCALL_OBJ(stack, K_OBJ_STACK));
 
 	return z_impl_k_stack_push(stack, data);
 }
@@ -187,8 +187,8 @@
 static inline int z_vrfy_k_stack_pop(struct k_stack *stack,
 				     stack_data_t *data, k_timeout_t timeout)
 {
-	Z_OOPS(K_SYSCALL_OBJ(stack, K_OBJ_STACK));
-	Z_OOPS(K_SYSCALL_MEMORY_WRITE(data, sizeof(stack_data_t)));
+	K_OOPS(K_SYSCALL_OBJ(stack, K_OBJ_STACK));
+	K_OOPS(K_SYSCALL_MEMORY_WRITE(data, sizeof(stack_data_t)));
 	return z_impl_k_stack_pop(stack, data, timeout);
 }
 #include <syscalls/k_stack_pop_mrsh.c>