Added changes for Raspi I2C

src/bus/interface.cpp

@@ -12,18 +12,18 @@ namespace sta
 
     void Interface::acquire()
     {
-        if (mutex_ != nullptr)
-            mutex_->acquire();
+        mutex_->acquire();
+        acquired_ = true;
     }
 
     void Interface::release()
     {
-        if (mutex_ != nullptr)
-            mutex_->release();
+        mutex_->release();
+        acquired_ = false;
     }
 
     bool Interface::isAquired()
     {
-        return aquired_;
+        return acquired_;
     }
 } // namespace sta