Improve compatibility with new CMake macro

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

kf5-sonnet.spec

@@ -1,3 +1,4 @@
+%undefine __cmake_in_source_build
 %global framework sonnet
 
 # uncomment to enable bootstrap mode
@@ -68,17 +69,13 @@ GUI part of the Sonnet framework provides widgets with spell checking support.
 
 
 %build
-mkdir %{_target_platform}
+%{cmake_kf5} \
-pushd %{_target_platform}
-%{cmake_kf5} .. \
   %{?tests:-DBUILD_TESTING:BOOL=ON}
-popd
+%cmake_build
-
-%make_build -C %{_target_platform}
 
 
 %install
-make install/fast DESTDIR=%{buildroot} -C %{_target_platform}
+%cmake_install
 
 %find_lang_kf5 sonnet5_qt