gcc build fix for protoprofile switch

Change-Id: Ifb34e2a5f1251fb75801bad7add4ea4c47dce557
diff --git a/tools/protoprofile/main.cc b/tools/protoprofile/main.cc
index d507e3c..5da8ad3 100644
--- a/tools/protoprofile/main.cc
+++ b/tools/protoprofile/main.cc
@@ -122,6 +122,7 @@
     case protozero::proto_utils::ProtoWireType::kFixed64:
       return 8;
   }
+  PERFETTO_FATAL("unexpected field type");  // for gcc
 }
 
 int SizeProfileComputer::InternString(const std::string& s) {