fix for JDK-8262122 fails validate-source

[2021-03-04T17:14:06,113Z] BAD COPYRIGHT LINE: /opt/mach5/mesos/work_dir/slaves/983c483a-6907-44e0-ad29-98c7183575e2-S14645/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/3b57b746-4b3c-4716-85c4-c2d0d0e09970/runs/cb9b40e1-c2b6-45a4-94d0-1dc74dfbaf66/workspace/open/test/hotspot/jtreg/gc/shenandoah/TestReferenceRefersToShenandoah.java
[2021-03-04T17:14:06,113Z] 1 header format error(s).
[2021-03-04T17:14:06,119Z] HandleGplSource.gmk:146: recipe for target '/opt/mach5/mesos/work_dir/slaves/983c483a-6907-44e0-ad29-98c7183575e2-S14645/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/3b57b746-4b3c-4716-85c4-c2d0d0e09970/runs/cb9b40e1-c2b6-45a4-94d0-1dc74dfbaf66/workspace/build/validate-source/support/header_validated/_test_hotspot_validated' failed
[2021-03-04T17:14:06,119Z] make[3]: *** [/opt/mach5/mesos/work_dir/slaves/983c483a-6907-44e0-ad29-98c7183575e2-S14645/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/3b57b746-4b3c-4716-85c4-c2d0d0e09970/runs/cb9b40e1-c2b6-45a4-94d0-1dc74dfbaf66/workspace/build/validate-source/support/header_validated/_test_hotspot_validated] Error 1
[2021-03-04T17:14:06,119Z] make[3]: *** Waiting for unfinished jobs....
[2021-03-04T17:14:07,460Z] /opt/mach5/mesos/work_dir/slaves/983c483a-6907-44e0-ad29-98c7183575e2-S14645/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/3b57b746-4b3c-4716-85c4-c2d0d0e09970/runs/cb9b40e1-c2b6-45a4-94d0-1dc74dfbaf66/workspace/closed/make/Main.gmk:67: recipe for target 'validate-headers' failed
[2021-03-04T17:14:07,460Z] make[2]: *** [validate-headers] Error 2
[2021-03-04T17:14:07,460Z] make[2]: *** Waiting for unfinished jobs....