smb: client: allow creating special files via reparse points

Add support for creating special files (e.g. char/block devices,
sockets, fifos) via NFS reparse points on SMB2+, which are fully
supported by most SMB servers and documented in MS-FSCC.

smb2_get_reparse_inode() creates the file with a corresponding reparse
point buffer set in @iov through a single roundtrip to the server.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311260746.HOJ039BV-lkp@intel.com/


Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>