[bugfix] Fix the application of the build flags

The '%{set_build_flags}' is unnecessary.
These flags are automatically called on the beginning of '%build' phase,
and are also part fo the '%cmake' macro.

The second call of CMake has to be run in "-N" mode,
which treats the CMake cache as read-only.

galera.spec

@@ -42,9 +42,8 @@ description of Galera replication engine see https://www.galeracluster.com web.
 %patch -P1 -p1
 
 %build
-%{set_build_flags}
 
-%cmake . \
+%cmake \
        -DCMAKE_BUILD_TYPE="%{?with_debug:Debug}%{!?with_debug:RelWithDebInfo}" \
        -DINSTALL_LAYOUT=RPM \
        -DCMAKE_RULE_MESSAGES:BOOL=OFF \
@@ -59,7 +58,7 @@ description of Galera replication engine see https://www.galeracluster.com web.
        -DINSTALL_LIBDIR="%{_lib}/galera" \
        -DINSTALL_MANPAGE="share/man/man8"
 
-cmake -B %_vpath_builddir -LAH
+cmake -B %_vpath_builddir -N -LAH
 
 %cmake_build