pySim-prog.py: Resolve possible variable use before assignment

pySim-prog.py:741:7: E0606: Possibly using variable 'cp' before assignment (possibly-used-before-assignment)

Change-Id: I6ab307db378d2ca76dfeae53dc3befa7c103974d

pySim-prog.py

@@ -723,6 +723,7 @@ def process_card(scc, opts, first, ch):
             card.erase()
             card.reset()
 
+    cp = None
     # Generate parameters
     if opts.source == 'cmdline':
         cp = gen_parameters(opts)