testsuite: allow tests to work in paths containing spaces

Tweak some tests so they work when the path to the test directory or
$HOME contains spaces.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/testsuite/sum.tests b/testsuite/sum.tests
index b9f4cbf..e637934 100755
--- a/testsuite/sum.tests
+++ b/testsuite/sum.tests
@@ -13,12 +13,12 @@
 #   test can create a file "actual" instead of writing to stdout
 
 testing "sum -r file doesn't print file's name" \
-        "sum -r $0 | grep -c $0 && echo wrongly_printed_filename || echo yes" \
+        "sum -r '$0' | grep -c '$0' && echo wrongly_printed_filename || echo yes" \
 	"0\nyes\n" "" ""
 testing "sum -r file file does print both names" \
-        "sum -r $0 $0 | grep -c $0 && echo yes || echo wrongly_omitted_filename" \
+        "sum -r '$0' '$0' | grep -c '$0' && echo yes || echo wrongly_omitted_filename" \
 	"2\nyes\n" "" ""
 testing "sum -s file does print file's name" \
-        "sum -s $0 | grep -c $0 && echo yes || echo wrongly_omitted_filename" \
+        "sum -s '$0' | grep -c '$0' && echo yes || echo wrongly_omitted_filename" \
 	"1\nyes\n" "" ""
 exit $FAILCOUNT