cifs: add SMB2_ioctl_init/free helpers to be used with compounding

Define an _init() and a _free() function for SMB2_init so that we will
be able to use it with compounds.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index 72cc563..3c32d0c 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -144,6 +144,10 @@ extern int SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon,
 		     u64 persistent_fid, u64 volatile_fid, u32 opcode,
 		     bool is_fsctl, char *in_data, u32 indatalen,
 		     char **out_data, u32 *plen /* returned data len */);
+extern int SMB2_ioctl_init(struct cifs_tcon *tcon, struct smb_rqst *rqst,
+			   u64 persistent_fid, u64 volatile_fid, u32 opcode,
+			   bool is_fsctl, char *in_data, u32 indatalen);
+extern void SMB2_ioctl_free(struct smb_rqst *rqst);
 extern int SMB2_close(const unsigned int xid, struct cifs_tcon *tcon,
 		      u64 persistent_file_id, u64 volatile_file_id);
 extern int SMB2_close_flags(const unsigned int xid, struct cifs_tcon *tcon,