[S390] make appldata compile w/o CONFIG_SWAP

Avoid compile error by using EXPORT_SYMBOL_GPL(si_swapinfo) only if
CONFIG_SWAP is set.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

arch/s390/appldata/appldata_base.c

@@ -584,7 +584,9 @@ EXPORT_SYMBOL_GPL(appldata_register_ops);
 EXPORT_SYMBOL_GPL(appldata_unregister_ops);
 EXPORT_SYMBOL_GPL(appldata_diag);
 
+#ifdef CONFIG_SWAP
 EXPORT_SYMBOL_GPL(si_swapinfo);
+#endif
 EXPORT_SYMBOL_GPL(nr_threads);
 EXPORT_SYMBOL_GPL(nr_running);
 EXPORT_SYMBOL_GPL(nr_iowait);