mesa: Draw indirect is not allowed if the default VAO is bound.

mesa: Draw indirect is not allowed if the default VAO is bound.

From OpenGL ES 3.1 specification, section 10.5:
"DrawArraysIndirect requires that all data sourced for the
command, including the DrawArraysIndirectCommand
structure,  be in buffer objects,  and may not be called when
the default vertex array object is bound."

Signed-off-by: Marta Lofstedt <marta.lofstedt@linux.intel.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>