cifs: use SPDX-Licence-Identifier

Add SPDX license identifier and replace license boilerplate.
Corrects various checkpatch errors with the older format for
noting the LGPL license.

Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 2343378..58ebec4 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: LGPL-2.1
 /*
  *   fs/cifs/cifssmb.c
  *
@@ -6,19 +7,6 @@
  *
  *   Contains the routines for constructing the SMB PDUs themselves
  *
- *   This library is free software; you can redistribute it and/or modify
- *   it under the terms of the GNU Lesser General Public License as published
- *   by the Free Software Foundation; either version 2.1 of the License, or
- *   (at your option) any later version.
- *
- *   This library is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
- *   the GNU Lesser General Public License for more details.
- *
- *   You should have received a copy of the GNU Lesser General Public License
- *   along with this library; if not, write to the Free Software
- *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 
  /* SMB/CIFS PDU handling routines here - except for leftovers in connect.c   */