RFR: 8314148: Fix variable scope in SunMSCAPI [v2]

[Daniel Jeliński]

> Please review this patch that fixes the scope of 2 local variables to make sure they are in scope when they are used.
> 
> The patch additionally fixes one `c++11-narrowing` Clang warning by explicitly casting string size (`size_t`) to `DWORD`.

Daniel Jeliński has updated the pull request incrementally with one additional commit since the last revision:

  fix verify method, reduce variable scope

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/15242/files
  - new: https://git.openjdk.org/jdk/pull/15242/files/ea9b8caa..e66639c6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15242&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15242&range=00-01

  Stats: 8 lines in 1 file changed: 4 ins; 4 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15242.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15242/head:pull/15242

PR: https://git.openjdk.org/jdk/pull/15242