Fix user actions without a trailing semicolon.

Reported by Sergei Steshenko at
<http://lists.gnu.org/archive/html/bug-bison/2008-11/msg00001.html>.
* THANKS (Sergei Steshenko): Add.
* src/scan-code.l (SC_RULE_ACTION): Fix it.
* tests/regression.at (Fix user actions without a trailing semicolon):
New test case.

THANKS

@@ -79,6 +79,7 @@ Robert Anisko             [email protected]
 Satya Kiran Popuri        [email protected]
 Sebastien Fricker         [email protected]
 Sebastian Setzer          [email protected]
+Sergei Steshenko          [email protected]
 Shura                     [email protected]
 Steve Murphy              [email protected]
 Tim Josling               [email protected]