tools/python: Correct the install path of the python scripts

c/s 74a7c7a was actually written long before c/s 2c96ecb "Use
configure --libexecdir=BASEDIR to set LIBEXEC", and I didn't notice
during development because of the method I was using to run a legacy
and migration v2 libxl toolstack side-by-side.

The result is that the conversion script gets installed in the root of
the output tree, rather than in the location libxl is expecting to
find it.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

tools/python/Makefile

@@ -17,12 +17,12 @@ build: genwrap.py $(XEN_ROOT)/tools/libxl/libxl_types.idl \
 
 .PHONY: install
 install:
-	$(INSTALL_DIR) $(DESTDIR)$(PRIVATE_BINDIR)
+	$(INSTALL_DIR) $(DESTDIR)$(LIBEXEC_BIN)
 
 	CC="$(CC)" CFLAGS="$(PY_CFLAGS)" $(PYTHON) setup.py install \
 		$(PYTHON_PREFIX_ARG) --root="$(DESTDIR)" --force
 
-	$(INSTALL_PROG) scripts/convert-legacy-stream $(DESTDIR)$(PRIVATE_BINDIR)
+	$(INSTALL_PROG) scripts/convert-legacy-stream $(DESTDIR)$(LIBEXEC_BIN)
 
 .PHONY: test
 test: