auto_registry warning

[nlslatt]

vt/src/vt/registry/auto/auto_registry.cc: In function ‘vt::trace::TraceEntryIDType vt::auto_registry::theTraceID(const HandlerType&, vt::auto_registry::RegistryTypeEnum)’:
vt/src/vt/registry/auto/auto_registry.cc:123:1: error: control reaches end of non-void function [-Werror=return-type]
 }
 ^

In release mode, the assert on line 120 won't trigger, resulting in a compile warning.