build-sys: add missing $

Fixup for 25ee45f99.

diff --git a/Makefile.am b/Makefile.am
index f4ac471a1372b53408f83af372979136b4169c6a..a7b9e7f1299e928502687b0f94839fccca1bd121 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -3515,7 +3515,7 @@ sphinx-%:
        $(AM_V_at)echo Output has been generated in $(abs_top_builddir)/man/python-systemd/
 
 destdir-sphinx: all
-       dir="$(mktemp -d /tmp/systemd-install.XXXXXX)" && \
+       dir="$$(mktemp -d /tmp/systemd-install.XXXXXX)" && \
                $(MAKE) DESTDIR="$$dir" install && \
                $(MAKE) DESTDIR="$$dir" sphinx-html && \
                rm -rf "$$dir"