Update c_blob_mbed.tmpl

- critical.h is deprecated, replaced with "platform/mbed_critical.h"
- typo corrected

Author: 0x6d61726b

tools/flash_algo/c_blob_mbed.tmpl

@@ -16,9 +16,9 @@
 
 #include "flash_api.h"
 #include "flash_data.h"
-#include "critical.h"
+#include "platform/mbed_critical.h"
 
-// This file is automagically generated
+// This file is automatically generated
 
 #if DEVICE_FLASH