Fix printf warnings at -DDEBUG.

I must have not recompiled with debug printouts enabled since updating
the internal printf functions to have the gcc printf attribute, or
these warnings would surely have come up before.

unix/gtkwin.c

@@ -1928,7 +1928,7 @@ gint key_event(GtkWidget *widget, GdkEventKey *event, gpointer data)
                 sfree(old);
             }
             debug(" - final output, special, generic encoding = [%s]\n",
-                  charset_to_localenc(output_charset), string_string);
+                  string_string);
             sfree(string_string);
 #endif
             /*

utils.c

@@ -858,7 +858,7 @@ void debug_memdump(const void *buf, int len, bool L)
                 dputs("   ");          /* 3 spaces */
                 foo[i] = ' ';
             } else {
-                debug_printf("%c%02.2x",
+                debug_printf("%c%2.2x",
                         &p[i] != (unsigned char *) buf
                         && i % 4 ? '.' : ' ', p[i]
                     );