drm/amd/amdgpu_dm/mst: Remove unneeded edid assignment when destroying connectors

Doesn't do anything, noticed this while cleaning up some unrelated
stuff.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331205740.135525-2-lyude@redhat.comReviewed-by: Alex Deucher <alexdeucher@gmail.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c

@@ -140,7 +140,6 @@ dm_dp_mst_connector_destroy(struct drm_connector *connector)
 	struct amdgpu_encoder *amdgpu_encoder = amdgpu_dm_connector->mst_encoder;
 
 	kfree(amdgpu_dm_connector->edid);
-	amdgpu_dm_connector->edid = NULL;
 
 	drm_encoder_cleanup(&amdgpu_encoder->base);
 	kfree(amdgpu_encoder);