bug fix: SS was not declared in the spi_write_and_read(.. function

Revision:
7:efb143ea4191
Parent:
6:38fa8ac6e43b
--- a/platform_drivers.cpp	Fri Aug 30 15:47:06 2019 +0000
+++ b/platform_drivers.cpp	Mon Sep 02 11:42:58 2019 +0000
@@ -211,6 +211,8 @@
 	if (desc) {
 		// Unused variable - fix compiler warning
 	}
+	//Create the DigitalOut object, based on user-defined chip-select
+    DigitalOut SS(slave_selects[desc->chip_select]);
 
 	SS = GPIO_LOW; 							//!select SS
 	for(size_t byte = 0 ; byte < bytes_number ; byte++)