translate: fix buffer overflows

translate: fix buffer overflows

Because in draw we always inject position at slot 0 whenever
fragment shader would take the maximum number of inputs (32) it
meant that we had PIPE_MAX_ATTRIBS + 1 slots to translate, which
meant that we were crashing with fragment shaders that took
the maximum number of attributes as inputs. The actual max number
of attributes we need to translate thus is PIPE_MAX_ATTRIBS + 1.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: José Fonseca <jfonseca@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Reviewed-by: Matthew McClure <mcclurem@vmware.com>