emulator GLESv2: fixed (#16) NenaMark crashes on exit

The GL2Encoder::m_compressedTextureFormats  member wasn't initialized, so the d'tor
would sometimes crash trying to delete it. Also init m_num_compressedTextureFormats.

Change-Id: Iae423c16a84a4e454e0e1167f7478f9e2f6183c0
2 files changed