owfs: install python bindings in the correct location

The owfs build system has a pretty complicated way of configuring the
Python bindings. It ends up with setting PYSITEDIR to the host-python
site-packages path, and it still prepends DESTDIR to that.

As a simple fix, override PYSITEDIR with the correct value on the make
command line.

Fixes:
http://autobuild.buildroot.net/results/200/200846650641494290aa67d28ea6fb2c9351d4dc
http://autobuild.buildroot.net/results/99c/99c00248dd8b00071bcdbc73336cc276c68a4c16
and many more

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/owfs/owfs.mk

@@ -66,6 +66,13 @@ OWFS_MAKE_ENV += \
 	_python_prefix=/usr \
 	_python_exec_prefix=/usr
 OWFS_DEPENDENCIES += python host-swig
+# The configure scripts finds PYSITEDIR as the python_lib directory of
+# host-python, and then prepends DESTDIR in front of it. So we end up
+# installing things in $(TARGET_DIR)/$(HOST_DIR)/usr/lib/python which is
+# clearly wrong.
+# Patching owfs to do the right thing is not trivial, it's much easier to
+# override the PYSITEDIR variable in make.
+OWFS_EXTRA_MAKE_OPTS += PYSITEDIR=/usr/lib/python$(PYTHON_VERSION_MAJOR)/site-packages
 else
 OWFS_CONF_OPTS += --disable-owpython --without-python
 endif
@@ -75,6 +82,8 @@ ifeq ($(BR2_STATIC_LIBS),y)
 OWFS_CONF_OPTS += --disable-zero
 endif
 
+OWFS_MAKE = $(MAKE) $(OWFS_EXTRA_MAKE_OPTS)
+
 define OWFS_INSTALL_INIT_SYSV
 	$(INSTALL) -D -m 0755 $(OWFS_PKGDIR)S25owserver \
 		$(TARGET_DIR)/etc/init.d/S25owserver