drm/amd/display: Fix Potential Null Dereference

[what & why]
System hang after s4 regression points to code change here.
Removing possible NULL dereference.

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Gabe Teeger <gabe.teeger@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c

@@ -139,9 +139,9 @@ static void dcn35_disable_otg_wa(struct clk_mgr *clk_mgr_base, struct dc_state *
 		old_pipe->stream != new_pipe->stream &&
 		old_pipe->stream_res.tg == new_pipe->stream_res.tg &&
 		new_pipe->stream->link_enc && !new_pipe->stream->dpms_off &&
-		new_pipe->stream->link->link_enc->funcs->is_dig_enabled &&
-		new_pipe->stream->link->link_enc->funcs->is_dig_enabled(
-		new_pipe->stream->link->link_enc) &&
+		new_pipe->stream->link_enc->funcs->is_dig_enabled &&
+		new_pipe->stream->link_enc->funcs->is_dig_enabled(
+		new_pipe->stream->link_enc) &&
 		new_pipe->stream_res.stream_enc &&
 		new_pipe->stream_res.stream_enc->funcs->is_fifo_enabled &&
 		new_pipe->stream_res.stream_enc->funcs->is_fifo_enabled(new_pipe->stream_res.stream_enc);