spec: fix spec warning for /usr/include/ynl

JIRA: https://issues.redhat.com/browse/RHEL-101712

upstream:
commit 0e2ccfd3e31eb0c3c7dde558daeb1b71256a146e
Author: Jan Stancek <jstancek@redhat.com>
Date:   Fri May 30 03:37:12 2025 -0400

With the combination of build options "--without realtime --without debug
--without debuginfo --without ynl --without doc" in ELN, build produces a
warning:

RPM build warnings:
    File not found: /builddir/build/BUILD/kernel-6.16.0-build/BUILDROOT/usr/include/ynl

Put the exclude behind %{with_ynl} to avoid the warning.

Signed-off-by: Alexandra Hájková <ahajkova@redhat.com>

Author: sasshka

redhat/kernel.spec.template

@@ -3915,8 +3915,10 @@ fi\
 %files headers
 /usr/include/*
 %exclude %{_includedir}/cpufreq.h
+%if %{with_ynl}
 %exclude %{_includedir}/ynl
 %endif
+%endif
 
 %if %{with_cross_headers}
 %files cross-headers