build: Use $(LN_S) safely

The autoconf documentation recommends to always use this
construct when creating symbolic links with $(LN_S) to avoid
unexpected behavior.

src/Makefile.am

@@ -3078,8 +3078,8 @@ if WITH_NETWORK
 	    cp $(DESTDIR)$(confdir)/qemu/networks/default.xml.t \
 	      $(DESTDIR)$(confdir)/qemu/networks/default.xml && \
 	    rm $(DESTDIR)$(confdir)/qemu/networks/default.xml.t; }
-	$(LN_S) -f ../default.xml \
-	    $(DESTDIR)$(confdir)/qemu/networks/autostart/default.xml
+	( cd $(DESTDIR)$(confdir)/qemu/networks/autostart && \
+	    $(LN_S) -f ../default.xml default.xml )
 endif WITH_NETWORK
 
 uninstall-local:: uninstall-init uninstall-systemd

tools/Makefile.am

@@ -423,8 +423,8 @@ LIBVIRT_NSS_SYMBOL_FILE = \
 NSS_SO_VER = 1
 
 install-exec-hook:
-	cd $(DESTDIR)$(libdir) && \
-	  $(LN_S) -f libnss_libvirt.so.$(NSS_SO_VER) nss_libvirt.so.$(NSS_SO_VER)
+	( cd $(DESTDIR)$(libdir) && \
+	  $(LN_S) -f libnss_libvirt.so.$(NSS_SO_VER) nss_libvirt.so.$(NSS_SO_VER) )
 
 uninstall-local:
 	-rm -f $(DESTDIR)$(libdir)/nss_libvirt.so.$(NSS_SO_VER)