cifs: zero-range does not require the file is sparse

Remove the conditional to fail zero-range if the file is not flagged as sparse.
You can still zero out a range in SMB2 even for non-sparse files.

Tested with stock windows16 server.

Fixes 5 xfstests (033, 149, 155, 180, 349)
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/smb2ops.c

@@ -2679,18 +2679,6 @@ static long smb3_zero_range(struct file *file, struct cifs_tcon *tcon,
 			return rc;
 		}
 
-	/*
-	 * Must check if file sparse since fallocate -z (zero range) assumes
-	 * non-sparse allocation
-	 */
-	if (!(cifsi->cifsAttrs & FILE_ATTRIBUTE_SPARSE_FILE)) {
-		rc = -EOPNOTSUPP;
-		trace_smb3_zero_err(xid, cfile->fid.persistent_fid, tcon->tid,
-			      ses->Suid, offset, len, rc);
-		free_xid(xid);
-		return rc;
-	}
-
 	cifs_dbg(FYI, "offset %lld len %lld", offset, len);
 
 	fsctl_buf.FileOffset = cpu_to_le64(offset);