Improve compatibility with new CMake macro

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

kf5-kdesignerplugin.spec

@@ -1,3 +1,4 @@
+%undefine __cmake_in_source_build
 %global framework kdesignerplugin
 
 # uncomment to enable bootstrap mode
@@ -57,16 +58,12 @@ from ini-style description files.
 
 
 %build
-mkdir %{_target_platform}
+%{cmake_kf5}
-pushd %{_target_platform}
+%cmake_build
-%{cmake_kf5} ..
-popd
-
-%make_build -C %{_target_platform}
 
 
 %install
-make install/fast DESTDIR=%{buildroot} -C %{_target_platform}
+%cmake_install
 
 %find_lang_kf5 kdesignerplugin5_qt
 # manpages