i965/vec4: Delete some dead code in visit(ir_expression *).

Nothing uses the vector_elements temporary variable.

Setting this->result.file is dead because we overwrite this->result a
few lines later.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>

src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp

@@ -1289,14 +1289,6 @@ vec4_visitor::visit(ir_expression *ir)
       assert(!ir->operands[operand]->type->is_matrix());
    }
 
-   int vector_elements = ir->operands[0]->type->vector_elements;
-   if (ir->operands[1]) {
-      vector_elements = MAX2(vector_elements,
-			     ir->operands[1]->type->vector_elements);
-   }
-
-   this->result.file = BAD_FILE;
-
    /* Storage for our result.  Ideally for an assignment we'd be using
     * the actual storage for the result here, instead.
     */