i965: Shut up a compiler warning about uninitialized var.

We always pass this argument, even if it won't be used by the particular
texture op.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

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

@@ -1494,7 +1494,7 @@ fs_visitor::nir_emit_texture(nir_tex_instr *instr)
    bool is_cube_array = instr->sampler_dim == GLSL_SAMPLER_DIM_CUBE &&
                         instr->is_array;
 
-   int lod_components, offset_components = 0;
+   int lod_components = 0, offset_components = 0;
 
    fs_reg coordinate, shadow_comparitor, lod, lod2, sample_index, mcs, offset;