build: Move configure.ac comment into actual AC_CASE
diff --git a/configure.ac b/configure.ac
index 5fc132c..e2686db 100644
--- a/configure.ac
+++ b/configure.ac
@@ -44,9 +44,9 @@ AC_SUBST([TESTU01_LIBS])
AM_CONDITIONAL([HAVE_LIBTESTU01],
[test "x$ac_cv_lib_testu01_unif01_CreateExternGenBits" = "xyes"])
-# In old glibc versions (< 2.17) clock_gettime() is in librt.
AS_CASE([$host_os],
[*-gnu], [
+ # In old glibc versions (< 2.17) clock_gettime() is in librt.
saved_LIBS="$LIBS"
AC_SEARCH_LIBS([clock_gettime], [rt], [CLOCK_GETTIME_LIBS="-lrt"])
AC_SUBST([CLOCK_GETTIME_LIBS])