builddeb: include objtool binary in headers package

"objtool" is required for building external m dules if "Compile-time
stack metadata validation" is enabled.  Otherwise all builds based
on the headers package fail with:

 make[1]: Entering directory '/usr/src/linux-headers-4.6.0-rc6'
 make[2]: *** No rule to make target 'tools/objtool/objtool', needed by 'foo.o'.  Stop.
 Makefile:1598: recipe for target 'foo.ko' failed
 make[1]: *** [foo.ko] Error 2
 make[1]: Leaving directory '/usr/src/linux-headers-4.6.0-rc6'

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Michal Marek <mmarek@suse.com>

scripts/package/builddeb

@@ -322,6 +322,9 @@ fi
 
 # Build kernel header package
 (cd $srctree; find . -name Makefile\* -o -name Kconfig\* -o -name \*.pl) > "$objtree/debian/hdrsrcfiles"
+if grep -q '^CONFIG_STACK_VALIDATION=y' $KCONFIG_CONFIG ; then
+	(cd $srctree; find tools/objtool -type f -executable) >> "$objtree/debian/hdrsrcfiles"
+fi
 (cd $srctree; find arch/$SRCARCH/include include scripts -type f) >> "$objtree/debian/hdrsrcfiles"
 (cd $srctree; find arch/$SRCARCH -name module.lds -o -name Kbuild.platforms -o -name Platform) >> "$objtree/debian/hdrsrcfiles"
 (cd $srctree; find $(find arch/$SRCARCH -name include -o -name scripts -type d) -type f) >> "$objtree/debian/hdrsrcfiles"