drm/amdgpu/display: don't assert in set backlight function

stable inclusion
from stable-5.10.24
commit fd87d778642b4b97ecacb87925924a509b9a0b9b
bugzilla: 51348

--------------------------------

commit dfd8b7fb upstream.

It just spams the logs.
Reviewed-by: NNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: N  Weilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/gpu/drm/amd/display/dc/core/dc_link.c

@@ -2555,7 +2555,6 @@ bool dc_link_set_backlight_level(const struct dc_link *link,
 			if (pipe_ctx->plane_state == NULL)
 				frame_ramp = 0;
 		} else {
-			ASSERT(false);
 			return false;
 		}