[code-reflection] Integrated: Add return values to setArg kernel methods

[Gary Frost]

Sadly introduced a bug in last PR. 

Added previously ommited return true for CudaKernel::setArgXX methods.  They both now return true.

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

Commit messages:
 - Add return values to setArg kernel methods

Changes: https://git.openjdk.org/babylon/pull/390/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=390&range=00
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/babylon/pull/390.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/390/head:pull/390

PR: https://git.openjdk.org/babylon/pull/390