i965: Remove intel_buffer_object::source.

This was only used for BOs backed by system memory on i915.  With that
gone, there's nothing that even sets source to non-zero, so this is
purely dead code.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>

src/mesa/drivers/dri/i965/intel_buffer_objects.c

@@ -65,7 +65,6 @@ release_buffer(struct intel_buffer_object *intel_obj)
    drm_intel_bo_unreference(intel_obj->buffer);
    intel_obj->buffer = NULL;
    intel_obj->offset = 0;
-   intel_obj->source = 0;
 }
 
 /**
@@ -414,9 +413,6 @@ intel_bufferobj_buffer(struct intel_context *intel,
                        struct intel_buffer_object *intel_obj,
 		       GLuint flag)
 {
-   if (intel_obj->source)
-      release_buffer(intel_obj);
-
    if (intel_obj->buffer == NULL)
       intel_bufferobj_alloc_buffer(intel, intel_obj);
 

src/mesa/drivers/dri/i965/intel_buffer_objects.h

@@ -47,8 +47,6 @@ struct intel_buffer_object
    void *range_map_buffer;
    unsigned int range_map_offset;
    GLsizei range_map_size;
-
-   bool source;
 };