pygrub fsimage.so: Honour LDFLAGS when building

This seems to have been simply omitted.  Obviously this is needed when
building and not just when installing.  Passing only when installing
is ineffective.

Signed-off-by: Ian Jackson <ian.jackson@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>

tools/pygrub/Makefile

@@ -10,7 +10,7 @@ INSTALL_LOG = build/installed_files.txt
 all: build
 .PHONY: build
 build:
-	CC="$(CC)" CFLAGS="$(PY_CFLAGS)" $(PYTHON) setup.py build
+	CC="$(CC)" CFLAGS="$(PY_CFLAGS)" LDFLAGS="$(PY_LDFLAGS)" $(PYTHON) setup.py build
 
 .PHONY: install
 install: all