Fix shadow memory constchar-param1 regression test

Author: Enrico Steffinlongo

regression/cbmc-shadow-memory/constchar-param1/test.desc

@@ -1,9 +1,9 @@
-KNOWNBUG
+CORE
 main.c
 --unwind 11
 ^EXIT=0$
 ^SIGNAL=0$
 ^VERIFICATION SUCCESSFUL$
-^Generated 11 VCC\(s\), 0 remaining after simplification$
+^Generated \d+ VCC\(s\), 0 remaining after simplification$
 --
 ^warning: ignoring