tests: fix difflink test-case

Per upstream report:
https://www.mail-archive.com/bug-tar@gnu.org/msg05440.html

Version: 1.30-1

tar-1.30-tests-difflink.patch

@@ -0,0 +1,15 @@
+Per https://www.mail-archive.com/bug-tar@gnu.org/msg05440.html
+
+diff --git a/tests/difflink.at b/tests/difflink.at
+index eadfb08..4e01176 100644
+--- a/tests/difflink.at
++++ b/tests/difflink.at
+@@ -21,7 +21,7 @@ mkdir a
+ genfile -f a/x
+ ln -s x a/y
+ ln a/y a/z
+-tar cf a.tar a
++tar cf a.tar a/x a/y a/z
+ rm a/z
+ ln -s x a/z
+ tar df a.tar

tar.spec

@@ -21,6 +21,7 @@ Patch3:  tar-1.29-wildcards.patch
 Patch4:  tar-1.28-atime-rofs.patch
 Patch9:  tar-1.28-document-exclude-mistakes.patch
 Patch11: tar-1.28-sparse-inf-loops.patch
+Patch12: tar-1.30-tests-difflink.patch
 
 # run "make check" by default
 %bcond_without check
@@ -120,6 +121,9 @@ fi
 %{_infodir}/tar.info*
 
 %changelog
+* Tue Dec 19 2017 Pavel Raiskup <praiskup@redhat.com> - 1.30-1
+- testsuite fix per upstream report
+
 * Mon Dec 18 2017 Pavel Raiskup <praiskup@redhat.com> - 1.30-1
 - rebase to latest upstream release, per release notes
   http://lists.gnu.org/archive/html/info-gnu/2017-12/msg00011.html