Improve compatibility with new CMake macro

Signed-off-by: Igor Raits <ignatenkobrain@fedoraproject.org>

kf5-kirigami2.spec

@@ -1,3 +1,4 @@
+%undefine __cmake_in_source_build
 %global framework kirigami2
 
 # uncomment to enable bootstrap mode
@@ -75,17 +76,13 @@ developing applications that use %{name}.
 %if 0%{?rhel}==7
 . /opt/rh/devtoolset-7/enable
 %endif
-mkdir %{_target_platform}
-pushd %{_target_platform}
-%{cmake_kf5} .. \
+%{cmake_kf5} \
   -DBUILD_TESTING:BOOL=%{?tests:ON}%{!?tests:OFF}
-popd
-
-%make_build -C %{_target_platform}
+%cmake_build
 
 
 %install
-make install/fast DESTDIR=%{buildroot} -C %{_target_platform}
+%cmake_install
 
 %find_lang_kf5 libkirigami2plugin_qt