cifs: fix uninitialised var in smb2_compound_op()

Fix uninitialised variable @idata when calling smb2_compound_op() with
SMB2_OP_POSIX_QUERY_INFO.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/smb2inode.c

@@ -415,6 +415,7 @@ static int smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
 						tcon->tid);
 		break;
 	case SMB2_OP_POSIX_QUERY_INFO:
+		idata = ptr;
 		if (rc == 0 && cfile && cfile->symlink_target) {
 			idata->symlink_target = kstrdup(cfile->symlink_target, GFP_KERNEL);
 			if (!idata->symlink_target)