ksmbd: rename is_dot_dotdot to ksmbd_is_dot_dotdot

is_dot_dotdot() patch merged into stable kernels.
It is hard to maintain it using KERNEL_VERSION anymore.
So rename is_dot_dotdot to ksmbd_is_dot_dotdot, not using
KERNEL_VERSION.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

Author: namjaejeon

vfs.c

@@ -2659,13 +2659,11 @@ struct ksmbd_file *ksmbd_vfs_dentry_open(struct ksmbd_work *work,
 }
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 9, 0)
-static inline bool is_dot_dotdot(const char *name, size_t len)
+static inline bool ksmbd_is_dot_dotdot(const char *name, size_t len)
 {
 	return len && unlikely(name[0] == '.') &&
 		(len == 1 || (len == 2 && name[1] == '.'));
 }
-#endif
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 1, 0)
 static bool __dir_empty(struct dir_context *ctx, const char *name, int namlen,
@@ -2677,7 +2675,7 @@ static int __dir_empty(struct dir_context *ctx, const char *name, int namlen,
 	struct ksmbd_readdir_data *buf;
 
 	buf = container_of(ctx, struct ksmbd_readdir_data, ctx);
-	if (!is_dot_dotdot(name, namlen))
+	if (!ksmbd_is_dot_dotdot(name, namlen))
 		buf->dirent_count++;
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 1, 0)