Fixed a couple of checkers in the XBeeDevice class.
Fixed a couple of checkers in the XBeeDevice class.

Signed-off-by: Diego Escalona <2cc07d4527ddb8161307b5e41bc6a82cc360f0ff@digi.com>

brucetsao/XBeeJavaLibrary,GUBotDev/XBeeJavaLibrary,digidotcom/XBeeJavaLibrary