Use %make_build macro instead of plain make

This will enable parallel make and will make it possible for buildroots
to inject arguments to make by redefining the %__make macro.

https://docs.fedoraproject.org/en-US/packaging-guidelines/#_parallel_make

blktrace.spec

@@ -1,7 +1,7 @@
 Summary: Utilities for performing block layer IO tracing in the Linux kernel
 Name: blktrace
 Version: 1.2.0
-Release: 12%{?dist}
+Release: 13%{?dist}
 License: GPLv2+
 Source:  http://brick.kernel.dk/snaps/blktrace-%{version}.tar.bz2
 Url: http://brick.kernel.dk/snaps
@@ -32,7 +32,7 @@ sed -i '1s=^#!/usr/bin/python3=#!%{__python3}=' \
 	btt/{btt_plot.py,bno_plot.py}
 
 %build
-make CFLAGS="%{optflags} %{build_ldflags}" all
+%make_build CFLAGS="%{optflags} %{build_ldflags}" all
 
 %install
 rm -rf %{buildroot}
@@ -80,6 +80,9 @@ information about IO patterns.
 %{_mandir}/man1/iowatcher.*
 
 %changelog
+* Mon Feb 03 2020 Tom Stellard <tstellar@redhat.com> - 1.2.0-13
+- Use make_build macro instead of plain make
+
 * Tue Jan 28 2020 Fedora Release Engineering <releng@fedoraproject.org> - 1.2.0-12
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_32_Mass_Rebuild