Fix ignore pattern when comparing sane-desc outputs in testsuite

The old versions used plain `git describe` output leading to versions
like 1.0.32-265-g5ff049.  The `git-version-gen` scripts replaces the
first dash, `-`, with a period, `.`, for the benefit of other version
comparison tools and strips the `g` to save a byte.  So that leads to
versions like 1.0.32.265-5ff049.

testsuite/tools/Makefile.am

@@ -32,7 +32,7 @@ check.local:
 	for mode in ascii html-backends-split html-mfgs xml statistics usermap db udev udev+acl udev+hwdb hwdb plist hal hal-new; \
 	do \
 	  $(SANEDESC) -m $$mode -s $(srcdir)/data >$$mode.res ;\
-	  if diff -I "sane-backends 1\.0\.[0-9]\+\([-0-9a-fgdirty]\+\)\?$$" \
+	  if diff -I "sane-backends 1\.0\.[0-9]\+\([-.0-9a-fgdirty]\+\)\?$$" \
 	       $(srcdir)/data/$$mode.ref $$mode.res ; \
 	  then \
 		echo "PASS: sane-desc -m $$mode -s $(srcdir)/data"; \