RFR[10] 8185620: MSCAPI test leaves too many entries in keystore

[sha . jiang]

Hi,
Test sun/security/mscapi/SmallPrimeExponentP.java adds some entries into 
Windows-MY keystore, but it doesn't delete them before exit.
Please review this patch for the above issue.
Webrev: http://cr.openjdk.java.net/~jjiang/8185620/webrev.00/
Issue: https://bugs.openjdk.java.net/browse/JDK-8185620

Best regards,
John Jiang