strncpy was used to copy resource names, which fills the unused parts of
the buffer with '\0'.  The spec doesn't forbid this, but dEQP fails on
this behavior, presumably to try and catch overflow bugs.

Bug: angleproject:3562
Change-Id: Ifce2d690221b2403848cb8913f4753ec60dfffab
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1698647
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Reviewed-by: Jonah Ryan-Davis <jonahr@google.com>