ubifs: Fix 'hash' kernel-doc warning in auth.c

Fixes the following W=1 kernel build warning(s):

fs/ubifs/auth.c:66: warning: Excess function parameter 'hash' description in 'ubifs_prepare_auth_node'

Rename hash to inhash.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/auth.c

@@ -54,7 +54,7 @@ static int ubifs_hash_calc_hmac(const struct ubifs_info *c, const u8 *hash,
  * ubifs_prepare_auth_node - Prepare an authentication node
  * @c: UBIFS file-system description object
  * @node: the node to calculate a hash for
- * @hash: input hash of previous nodes
+ * @inhash: input hash of previous nodes
  *
  * This function prepares an authentication node for writing onto flash.
  * It creates a HMAC from the given input hash and writes it to the node.