use %make_build and %make_install macros

These macros do the same thing as the previous code.  They allow future
adjustments to the make command line to be more easily added.

ncdu.spec

@@ -24,10 +24,10 @@ and provides a fast way to see what directories are using your disk space.
 
 %build
 %configure
-make %{?_smp_mflags}
+%make_build
 
 %install
-make install DESTDIR=%{buildroot}
+%make_install
 
 %files
 %{_mandir}/man1/ncdu.1*
@@ -38,6 +38,7 @@ make install DESTDIR=%{buildroot}
 %changelog
 * Fri Dec 30 2022 Todd Zullinger <tmz@pobox.com> - 1.18-3
 - verify upstream signatures in %%prep
+- use %%make_build and %%make_install macros
 
 * Tue Dec 27 2022 Richard Fearn <richardfearn@gmail.com> - 1.18-2
 - Use SPDX license identifier