tar: port to Mingw Shell

* src/extract.c (extract_symlink) [!HAVE_SYMLINK]:
Fix typo by replacing WARN_SYMBOLIC_CAST with WARN_SYMLINK_CAST.
Problem reported by kaka in
<http://lists.gnu.org/archive/html/bug-tar/2013-06/msg00008.html>.

src/extract.c

@@ -1341,7 +1341,7 @@ extract_symlink (char *file_name, int typeflag)
   if (!warned_once)
     {
       warned_once = 1;
-      WARNOPT (WARN_SYMBOLIC_CAST,
+      WARNOPT (WARN_SYMLINK_CAST,
 	       (0, 0,
 		_("Attempting extraction of symbolic links as hard links")));
     }