drm/amdgpu: use true and false for bool initialisations

Bool initialisation should use 'true' and 'false' values instead of 0
and 1.

Modify amdgpu_amdkfd_gpuvm.c to initialise variable is_imported
to false instead of 0.

Issue found with Coccinelle.
Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1287,7 +1287,7 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
 	struct ttm_validate_buffer *bo_list_entry;
 	unsigned int mapped_to_gpu_memory;
 	int ret;
-	bool is_imported = 0;
+	bool is_imported = false;
 
 	mutex_lock(&mem->lock);
 	mapped_to_gpu_memory = mem->mapped_to_gpu_memory;