drm/amdgpu: return early for non-TTM_PL_TT type BOs

Return early for non-TTM_PL_TT BOs so that we don't pass
wrong pointer to amdgpu_gtt_mgr_has_gart_addr() which assumes
ttm_resource argument to be TTM_PL_TT type BO's.

v3: remove extra braces.
v2: merge if-conditions.

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210629114413.3371-1-nirmoy.das@amd.com

Author: Nirmoy Das

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

@@ -924,7 +924,8 @@ static int amdgpu_ttm_backend_bind(struct ttm_device *bdev,
 	    bo_mem->mem_type == AMDGPU_PL_OA)
 		return -EINVAL;
 
-	if (!amdgpu_gtt_mgr_has_gart_addr(bo_mem)) {
+	if (bo_mem->mem_type != TTM_PL_TT ||
+	    !amdgpu_gtt_mgr_has_gart_addr(bo_mem)) {
 		gtt->offset = AMDGPU_BO_INVALID_OFFSET;
 		return 0;
 	}