mesa: Set correct array element in vbo_exec_vtx_init.

mesa: Set correct array element in vbo_exec_vtx_init.

I'm not familiar with this code, but this sure appears to be a typo.
It looks like the intent is to set each array element, not arrays[0]
each time.  Notably, the loop just below uses "array", not "arrays".

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Fredrik Höglund <fredrik@kde.org>
Reviewed-by: Brian Paul <brianp@vmware.com>
Cc: mesa-stable@lists.freedesktop.org