Coverity static analysis: Useless call in Elytron

Coverity static-analysis scan found useless call in the FileSystemSecurityRealm.writeIdentity() method on line 554 (currently).
There is an orphan call of otp.getHash().
https://scan7.coverity.com/reports.htm#v16159/p11778/fileInstanceId=5721630&defectInstanceId=1531117&mergedDefectId=1369308

The correct call is on the line 557, where it's used in streamWriter.

Suggested improvement
Remove the useless call.