drm/i915: Remove unwanted ghost obj check

vm_fault_ttm() should not expect ttm ghost obj so remove that check.
Suggested-by: NMatthew Auld <matthew.auld@intel.com>
Signed-off-by: NNirmoy Das <nirmoy.das@intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Signed-off-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221024144558.27747-1-nirmoy.das@intel.com

drivers/gpu/drm/i915/gem/i915_gem_ttm.c

@@ -1030,9 +1030,6 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
 	vm_fault_t ret;
 	int idx;
 
-	if (i915_ttm_is_ghost_object(bo))
-		return VM_FAULT_SIGBUS;
-
 	/* Sanity check that we allow writing into this object */
 	if (unlikely(i915_gem_object_is_readonly(obj) &&
 		     area->vm_flags & VM_WRITE))