RFR(XS): 8132551: Initialize local variables before returning them in p11_convert.c

[Volker Simonis]

Hi,

can somebody please review these trivial change which initializes
local variables before they are returned as return values:

http://cr.openjdk.java.net/~simonis/webrevs/2015/8132551
https://bugs.openjdk.java.net/browse/JDK-8132551

Funny enough, this was objected by the Visual Studio compiler in the
slowdebug build only but not in the product or debug builds.

Thank you and best regards,
Volker