mesa: Move check for vbo mapping into api_validate.c.

mesa: Move check for vbo mapping into api_validate.c.

Instead of checking for mapped buffers in vbo_bind_arrays
do this check in api_validate.c. This additionally
enables printing the draw calls name into the error
string.

Signed-off-by: Mathias Fröhlich <Mathias.Froehlich@web.de>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Eric Anholt <eric@anholt.net>