utils: catch exceptions during reader initalitation

Failed reader initializations happen frome time to time, mostly because
of messed up commandline arguments. This results in ugly crashes very
often. Lets control this a bit by catching the exception string and
print it.

Change-Id: I313017355da01bbef7c3d3f1899555aadb509319

pySim-prog.py

@@ -720,6 +720,8 @@ if __name__ == '__main__':
 
 	# Init card reader driver
 	sl = init_reader(opts)
+	if sl is None:
+		exit(1)
 
 	# Create command layer
 	scc = SimCardCommands(transport=sl)