use patch to patch Makefile instead of sed

convmv.spec

@@ -6,6 +6,7 @@ Release: 1%{?dist}
 License: GPLv2 or GPLv3
 URL: http://j3e.de/linux/convmv
 Source0: http://j3e.de/linux/convmv/convmv-%{version}.tar.gz
+Patch0: convmv-2.0-preserve-timestamps.patch
 BuildArch: noarch
 
 %description
@@ -14,9 +15,8 @@ of filenames, e.g. from Latin1 to UTF-8.
 
 %prep
 %setup -q
+%patch0 -p1 -b .preserve-timestamps
 tar -xf testsuite.tar
-# This is needed to preserve the timestamp of convmv file
-sed -i 's/install/install -p/g' Makefile
 
 %build
 make %{_smp_mflags}
@@ -35,6 +35,7 @@ make PREFIX=%{_prefix} DESTDIR=%{buildroot} install
 %changelog
 * Tue May 19 2015 Nils Philippsen <nils@redhat.com> - 2.0-1
 - version 2.0
+- use patch to patch Makefile instead of sed
 
 * Sat Jun 07 2014 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 1.15-3
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_21_Mass_Rebuild