Use single quotes to make tests pass on Windows

Our use of test.pl requires single quotes for tests to the same way
across all platforms.

Author: tautschnig

regression/cbmc/export-symex-ready-goto/test-bad-usage.desc

@@ -1,6 +1,6 @@
 CORE winbug
 test.c
---export-symex-ready-goto ""
+--export-symex-ready-goto ''
 ^ERROR: Please provide a filename to write the goto-binary to.$
 ^EXIT=6$
 ^SIGNAL=0$

regression/goto-inspect/show-goto-functions/negative.desc

@@ -1,6 +1,6 @@
-CORE winbug
+CORE
 main.c
-" "
+' '
 ^EXIT=6$
 ^SIGNAL=0$
 --