GL43: Use zero for DrawArraysIndirectCommand reserved field

GL43: Use zero for DrawArraysIndirectCommand reserved field

The test negative-gshIncompatible-arrays is using a non-zero value for
the DrawArraysIndirectCommand reserved field, but quoting its Title,
Purpose and Method:

 "Negative: incompatible the input primitive type of gsh - glDrawArrayIndirect";

 "Verify that a driver sets error and no driver crash occurred";

 "1. Bind non-zero buffer"
 "2. Set data"
 "3. Set wrong geometry shader"
 "4. Call glDrawArrayIndirect"

Testing non-zero values for the reserved field is not one of its
objectives. This seems a C&P error.

Components: OpenGL

VK-GL-CTS issue: 2023

Affects:
KHR-GL43.draw_indirect.negative-gshIncompatible-arrays

Change-Id: I8f0676b3a82266fa41becdfb720b04893720b6fc