qtwayland-native/qtwaylandscanner: remove full path comment from generated files

Since Qt 5.15 qtwaylandscanner adds the source-xml-file which can be in sysroot.
That triggers our cmake_extra_sanity.bbclass. So remove comment - we did not
miss it in Qt < 5.15.

Signed-off-by: Andreas Müller <schnitzeltony@gmail.com>

extends-meta-qt5/qtwayland_git.bbappend

@@ -0,0 +1,16 @@
+# Since Qt5.15 qtwaylandscanner creates a comment as:
+
+# // source file is /home/superandy/tmp/oe-core-glibc/work/cortexa7t2hf-neon-vfpv4-mortsgna-linux-gnueabi/kwayland/5.70.0-r0/recipe-sysroot/usr/share/wayland-protocols/unstable/tablet/tablet-unstable-v2.xml
+
+# which triggers our make_extra_sanity.bbclass.
+# To be compatible with Qt5.14 (dunfell) and >= Qt5.15 (current master) we do
+# some sed instead of patching.
+do_patch_append_class-native() {
+    bb.build.exec_func('do_fix_qtwaylandscanner_cpp', d)
+}
+
+do_fix_qtwaylandscanner_cpp () {
+    if [ -f ${S}/src/qtwaylandscanner/qtwaylandscanner.cpp ]; then
+        sed -i 's:printf("// source file is://printf("// source file is:' ${S}/src/qtwaylandscanner/qtwaylandscanner.cpp
+    fi
+}