Add worker function to set allocation size

Adds setinfo worker function for SMB2/SMB3 support of SET_ALLOCATION_INFORMATION

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>

diff --cc fs/cifs/smb2inode.c
Simple merge

diff --cc fs/cifs/smb2ops.c
Simple merge

diff --cc fs/cifs/smb2pdu.c
Simple merge

diff --cc fs/cifs/smb2proto.h
Simple merge