build-sys: Always enable parallel tests
Automake < 1.13 doesn't enable parallel tests by default, so add it to our
automake options.
diff --git a/configure.ac b/configure.ac
index 066515c..fc514d2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -8,7 +8,7 @@
AC_CONFIG_SRCDIR([libkmod/libkmod.c])
AC_CONFIG_AUX_DIR([build-aux])
AM_INIT_AUTOMAKE([check-news foreign 1.11 silent-rules
- tar-pax no-dist-gzip dist-xz subdir-objects color-tests])
+ tar-pax no-dist-gzip dist-xz subdir-objects color-tests parallel-tests])
AC_PROG_CC_STDC
AC_USE_SYSTEM_EXTENSIONS
AC_SYS_LARGEFILE