Fix undefined behavior

Fixes undefined behavior where SDCardBlockDevice::wait_for_completition() runs off the end without returning a value.

Author: alrvid

libraries/BlockDevices/SDCardBlockDevice.cpp

@@ -478,7 +478,7 @@ fsp_err_t SDCardBlockDevice::wait_for_completition() {
 
       rv = FSP_ERR_TIMEOUT;
    }
-
+   return rv;
 }