build: don't clean a file that belongs in the tarball

Otherwise, 'make rpm' fails with:

make[2]: *** No rule to make target `locking/test_libvirt_sanlock.aug.in', needed by `distdir'.  Stop.
make[2]: Leaving directory `/home/dipankar/src/powerpc/libvirt-ppc/src'
make[1]: *** [distdir] Error 1

Reported by Dipankar Sarma.

* src/Makefile.am (CLEANFILES): Clean only the generated file.

src/Makefile.am

@@ -1359,7 +1359,7 @@ sanlock_la_LIBADD = -lsanlock_client \
 
 augeas_DATA += locking/libvirt_sanlock.aug
 augeastest_DATA += locking/test_libvirt_sanlock.aug
-CLEANFILES += locking/test_libvirt_sanlock.aug.in
+CLEANFILES += locking/test_libvirt_sanlock.aug
 
 $(builddir)/locking/%-sanlock.conf: $(srcdir)/locking/sanlock.conf
 	$(AM_V_GEN)$(MKDIR_P) locking ; \