These two are terse by default and don't respect the KBUILD_VERBOSE
environment variable.
(I considered adding V=1 to the MAKEFLAGS we use by default in
debian/rules.real, but this might have different semantics for the few
tools that aren't built using either kbuild or automake.)
It has a lintian error (non-empty-dependency_libs-in-la-file) and it
also seems to be missing a header (the newly added
usbip_host_common.h) since Linux 4.7. No-one seems to have noticed,
and it has nothing build-depending on it, so get rid of it.
Currently the linux-source-<version> package may or may not include
these files, depending on the order things are built in.
As autotools always modifies the source directory, copy (rsync) the
source to the build directory and build in-place there.
Some years back I patched the #include of <linux/usbip.h> to include
the current, uninstalled version through a relative path because the
system-installed version will normally be outdated. We're about to
start copying the source to avoid writing autotools crap into the
source directory, which breaks this relative path.
Since we now install the UAPI headers under debian/build at the start
of the tools build, drop the patch and add that directory to the
include path.
Pass $(CROSS_COMPILE) or host GNU type through to upstream build rules.
debian/rules.real: Filter tools packages by host arch, not build arch
debian/rules.d/Makefile: Build the tools needed for headers_install in
a separate subdirectory
By passing both -C and -f options to make, we can separate makefiles
from the output directory without adding prefixes to all targets.
We can also reduce the 'clean' commands to little more than 'rm -rf'.