Qnx: Fix Abi detection for remote toolchains

We were suddenly ending up looking into the local file system.

Change-Id: I4911206e6d29f10a9dfaa9bc97307b28e383c14c
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/qnx/qnxtoolchain.cpp

@@ -54,7 +54,7 @@ static Abis detectTargetAbis(const FilePath &sdpPath)
         const EnvironmentItems environment = QnxUtils::qnxEnvironment(sdpPath);
         for (const EnvironmentItem &item : environment) {
             if (item.name == QLatin1String("QNX_TARGET"))
-                qnxTarget = FilePath::fromString(item.value);
+                qnxTarget = sdpPath.withNewPath(item.value);
         }
     }