cifsd: fix wrong prototype in comment

kernel test robot reported:
 >> fs/cifsd/oplock.c:1454: warning: expecting prototype for
    create_durable_rsp__buf(). Prototype was for
    create_durable_rsp_buf() instead

This patch fix wrong prototype in comment.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifsd/oplock.c

@@ -1436,7 +1436,7 @@ struct create_context *smb2_find_context_vals(void *open_req, const char *tag)
 }
 
 /**
- * create_durable_rsp__buf() - create durable handle context
+ * create_durable_rsp_buf() - create durable handle context
  * @cc:	buffer to create durable context response
  */
 void create_durable_rsp_buf(char *cc)