HAWQ-1535. Link PXF jars only if pxf home is set
diff --git a/pxf/Makefile b/pxf/Makefile
index 92e11e7..1bd8002 100644
--- a/pxf/Makefile
+++ b/pxf/Makefile
@@ -93,11 +93,12 @@
 
 install:
 	./gradlew install $(BUILD_PARAMS)
-	# Create symlink for PXF jars
+ifneq "$(PXF_HOME)" ""
 	@pushd $(PXF_HOME)/lib && \
 	    for X in pxf-*-[0-9]*.jar; do \
             ln -sf $$X `echo $$X | sed -e 's/-[a-zA-Z0-9.]*.jar/.jar/'`; \
         done && popd
+endif
 
 bundle:
 	./gradlew bundle $(BUILD_PARAMS)