surfaceflinger: fix duplicate layer name logspam

Prevent the duplicate layer name from showing up in the logs.
It is not very informative and it causes bugs to be incorrectly
routed to surfaceflinger maintainers.

Bug: 76207061
Test: boot device and verify "duplicate layer name" is no longer
      in logcat output

Change-Id: I16b59984401b6defb428ceb211f114446556f0a4