audit: Fix some kernel-doc warnings

The current code provokes some kernel-doc warnings:
    security/lsm_audit.c:198: warning: Function parameter or member
      'ab' not described in 'dump_common_audit_data'
Signed-off-by: Bo Liu <liubo03@inspur.com>
[PM: description line wrap]
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/lsm_audit.c

@@ -190,6 +190,7 @@ static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
 
 /**
  * dump_common_audit_data - helper to dump common audit data
+ * @ab : the audit buffer
  * @a : common audit data
  *
  */