Use make macros

https://fedoraproject.org/wiki/Changes/UseMakeBuildInstallMacro

gimp.spec

@@ -89,7 +89,7 @@ Name:           gimp
 Epoch:          2
 Version:        2.10.20
 %global rel 2
-Release:        %{?prerelprefix}%{rel}%{dotprerel}%{dotgitrev}%{?dist}
+Release:        %{?prerelprefix}%{rel}%{dotprerel}%{dotgitrev}%{?dist}.1
 
 # Compute some version related macros.
 # Ugly, need to get quoting percent signs straight.
@@ -395,7 +395,7 @@ export RHEL_ALLOW_PYTHON2_FOR_BUILD=1
 %endif
     --without-appdata-test
 
-make %{?_smp_mflags}
+%make_build
 
 %if ! %{unstable}
 # Generate RPM macros from pkg-config data:
@@ -444,7 +444,7 @@ EOF
 %endif
 
 %install
-make DESTDIR=%{buildroot} install
+%make_install
 %if ! %unstable
 install -D -m0644 macros.gimp %{buildroot}%{_rpmconfigdir}/macros.d/macros.gimp
 %endif
@@ -718,6 +718,10 @@ make check %{?_smp_mflags}
 %endif
 
 %changelog
+* Mon Jul 13 2020 Tom Stellard <tstellar@redhat.com> - 2:2.10.20-2.1
+- Use make macros
+- https://fedoraproject.org/wiki/Changes/UseMakeBuildInstallMacro
+
 * Wed Jun 24 2020 Josef Ridky <jridky@redhat.com> - 2:2.10.20-2
 - fix issue with liblcms2 in rawhide (#1850141)