drm/i915: Fix test on inputs for vma_compare()

drm/i915: Fix test on inputs for vma_compare()

When supplying a view to vma_compare() it is required that the supplied
i915_address_space is the global GTT. I tested the VMA instead (which is
the current position in the rbtree and maybe from any address space).

(This reapplies commit a44342acde30 ("drm/i915: Fix test on inputs for
vma_compare()") as it was lost in the vma split)

Reported-by: Matthew Auld <[email protected]>
Tested-by: Matthew Auld <[email protected]>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98579
Fixes: db6c2b4151f2 ("drm/i915: Store the vma in an rbtree...")
Signed-off-by: Chris Wilson <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Matthew Auld <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Matthew Auld <[email protected]>
Reported-by: Paulo Zanoni <[email protected]>
Fixes: b42fe9ca0a1e ("drm/i915: Split out i915_vma.c")
Cc: Joonas Lahtinen <[email protected]>