Fix Krazy code scanning tool warnings (QString, loops, spelling).

src/plugins/debugger/gdb/classicgdbengine.cpp

@@ -280,7 +280,7 @@ void GdbEngine::updateSubItemClassic(const WatchData &data0)
         if (debuggerCore()->boolSetting(AutoDerefPointers)) {
             // Try automatic dereferentiation
             data.exp = "(*(" + data.exp + "))";
-            data.type = data.type + "."; // FIXME: fragile HACK to avoid recursion
+            data.type = data.type + '.'; // FIXME: fragile HACK to avoid recursion
             insertData(data);
         } else {
             data.setChildrenUnneeded();

src/plugins/debugger/gdb/codagdbadapter.cpp

@@ -597,7 +597,7 @@ void CodaGdbAdapter::handleGdbServerCommand(const QByteArray &cmd)
         sendGdbServerAck();
         logMessage(_("Not implemented 'Continue with signal' %1: ").arg(signalNumber),
             LogWarning);
-        sendGdbServerMessage("O" + QByteArray("Console output").toHex());
+        sendGdbServerMessage('O' + QByteArray("Console output").toHex());
         sendGdbServerMessage("W81"); // "Process exited with result 1
         sendTrkContinue();
     }

src/plugins/debugger/gdb/gdbengine.cpp

@@ -2782,7 +2782,7 @@ void GdbEngine::requestModuleSymbols(const QString &moduleName)
     QString fileName = tf.fileName();
     tf.close();
     postCommand("maint print msymbols " + fileName.toLocal8Bit()
-            + " " + moduleName.toLocal8Bit(),
+            + ' ' + moduleName.toLocal8Bit(),
         NeedsStop, CB(handleShowModuleSymbols),
         QVariant(moduleName + QLatin1Char('@') +  fileName));
 }

src/plugins/debugger/gdb/trkgdbadapter.cpp

@@ -837,7 +837,7 @@ void TrkGdbAdapter::handleGdbServerCommand(const QByteArray &cmd)
         }
     } // qPart/qXfer
 
-    else if (cmd.startsWith("X")) {
+    else if (cmd.startsWith('X')) {
         logMessage(msgGdbPacket(QLatin1String("Write memory")));
         // X addr,length
         sendGdbServerAck();