BUG: Fix Win MultiThreader check for successful process creation.

Need to access the array item.

Also fix style of related code for readability.

Change-Id: I0f640aac4266fa5c0df67991ab71b5ffb218fcae
Merge branch 'master' into MultiThreaderIndex_release

Conflicts:
	Modules/Core/Common/src/itkMultiThreaderWinThreads.cxx

Change-Id: Ieb831eb633090326daabbd5725b98c77372e1735
Merge topic 'MultiThreaderIndex_release'

08672207 Merge branch 'master' into MultiThreaderIndex_release
869312e0 BUG: Fix Win MultiThreader check for successful process creation.