libstb_hal: Suppress implicit-fallthrough warnings from GCC 7

Origin commit data
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Branch: master
Commit: 66f36919a2
Author: GetAway <get-away@t-online.de>
Date: 2019-06-14 (Fri, 14 Jun 2019)


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No further description and justification available within origin commit message!

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This commit was generated by Migit

libdvbci/dvbci_camgr.cpp

@@ -85,6 +85,7 @@ int eDVBCICAManagerSession::doAction()
 		}
 		case stateFinal:
 			printf("[CI CA] stateFinal and action should not happen\n");
+			// fall through
 		default:
 			return 0;
 	}