test_multiples uses hard-coded MAX_DEVICES, but passes actual devices count to test_device_set

test_multiples uses hard-coded MAX_DEVICES, but passes actual devices count to test_device_set.
This may fail actual device-count exceeds MAX_DEVICES.
So, either test should dynamically allocate size of device array or cap the number of devices passed to test_device_set to minimum of deviceCount and MAX_DEVICES.
(Although MAX_DEVICES is now reasonably large (32) compared to earlier limit of 8, we can soon exceed MAX_DEVICES for data-center or cloud-based setup and we will have the same problem again)

Locate the test_multiples code and the definitions or call sites for MAX_DEVICES and test_device_set. Check how the actual device count is obtained and choose a bounded or dynamically sized device array approach. Done means the test remains safe when the device count exceeds MAX_DEVICES and the relevant OpenCL CTS tests pass.

Written by the indexing model from the issue text.