winedump: null pointer dereference in spec mode

[Tillmann Werner]

diff -Naur a/tools/winedump/pe.c b/tools/winedump/pe.c
--- a/tools/winedump/pe.c       2010-01-05 22:12:04.000000000 +0100
+++ b/tools/winedump/pe.c       2010-01-05 22:11:17.000000000 +0100
@@ -1631,7 +1631,7 @@
  */
 int dll_next_symbol (parsed_symbol * sym)
 {
-    if (!dll_current_symbol->symbol)
+    if (!dll_current_symbol || !dll_current_symbol->symbol)
        return 1;

     assert (dll_symbols);