ensure to lock params for whole transaction

Author: smarq8

libraries/SPI/src/SPI.cpp

@@ -165,14 +165,14 @@ void SPIClass::beginTransaction(SPISettings settings)
     }
     spiTransaction(_spi, _div, settings._dataMode, settings._bitOrder);
     _inTransaction = true;
-    SPI_PARAM_UNLOCK();
 }
 
 void SPIClass::endTransaction()
 {
     if(_inTransaction){
         _inTransaction = false;
         spiEndTransaction(_spi);
+	SPI_PARAM_UNLOCK();
     }
 }