cmd: Fix issue in WCMD_assoc highlighted by valgrind.

In an error condition, the wrong variable was being used for an insert,
resulting in a read from uninitialized data. This could be triggered for
example by 'ftype jason=', and the error message should have included
jason but instead was just ''.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=38849
Signed-off-by: Jason Edmeades <us@edmeades.me.uk>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

programs/cmd/builtins.c

@@ -4923,7 +4923,7 @@ void WCMD_assoc (const WCHAR *args, BOOL assoc) {
               LoadStringW(hinst, WCMD_NOFTYPE, msgbuffer,
                           sizeof(msgbuffer)/sizeof(WCHAR));
             }
-            WCMD_output_stderr(msgbuffer, keyValue);
+            WCMD_output_stderr(msgbuffer, args);
             errorlevel = 2;
           }