Fix runtime warnings from TGeant3

While accessing geometry information from TGeant3 a level outside of the
geometry hierarchy was requested.
Exit from loop when needed information is found.

refs #3092

core/detectors/fsd/CbmFsdGeoHandler.cxx

@@ -120,10 +120,15 @@ int32_t CbmFsdGeoHandler::GetCurrentAddress(TVirtualMC* vmc) const
 
   Int_t upstreamOffset = 0;
   while (((TString) vmc->CurrentVolOffName(upstreamOffset)).Length() > 0) {
-    if (((TString) vmc->CurrentVolOffName(upstreamOffset)).Contains(fUnitStr))
+    if (((TString) vmc->CurrentVolOffName(upstreamOffset)).Contains(fUnitStr)) {
       vmc->CurrentVolOffID(upstreamOffset, unitID);
-    if (((TString) vmc->CurrentVolOffName(upstreamOffset)).Contains(fModuleStr))
+    }
+    if (((TString) vmc->CurrentVolOffName(upstreamOffset)).Contains(fModuleStr)) {
       vmc->CurrentVolOffID(upstreamOffset, moduleID);
+    }
+    // if module and unit information was found one can
+    // exit the loop
+    if (moduleID > -1 && unitID > -1) { break; }
     upstreamOffset++;
   }