QHash: simplify HashSeedStorage::initialize()

By not splitting Q_UNREACHABLE() and the following return, we can get
rid of the NOLINT(qt-use-unreachable-return).

Change-Id: I3322843e38dabdadb38eea38a6d91b301257fd23
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qhash.cpp

@@ -107,8 +107,7 @@ private:
     StateResult result = { 0, OverriddenByEnvironment };
 #ifdef QT_BOOTSTRAPPED
     Q_UNUSED(which);
-    // NOLINTNEXTLINE(qt-use-unreachable-return): triggers on QT_BOOTSTRAPPED, breaking #else case
-    Q_UNREACHABLE();
+    Q_UNREACHABLE_RETURN(result);
 #else
     // can't use qEnvironmentVariableIntValue (reentrancy)
     const char *seedstr = getenv("QT_HASH_SEED");
@@ -138,8 +137,8 @@ private:
             result.requestedSeed = x.data[i];
     }
     result.state = JustInitialized;
-#endif
     return result;
+#endif
 }
 
 inline HashSeedStorage::StateResult HashSeedStorage::state(int which)