Fix underlinking in GCC 4.9 and below

--- bcache-tools-1.0.8/Makefile
+++ bcache-tools-1.0.8/Makefile
@@ -24,7 +24,7 @@
 make-bcache: LDLIBS += `pkg-config --libs uuid blkid`
 make-bcache: CFLAGS += `pkg-config --cflags uuid blkid`
 make-bcache: bcache.o
-probe-bcache: LDLIBS += `pkg-config --libs uuid blkid`
+probe-bcache: LDLIBS += `pkg-config --libs uuid blkid` bcache.o
 probe-bcache: CFLAGS += `pkg-config --cflags uuid blkid`
 bcache-super-show: LDLIBS += `pkg-config --libs uuid`
 bcache-super-show: CFLAGS += -std=gnu99