tools/liblockdep: Build liblockdep from tools/Makefile

add targets to build liblockdep with
make -C tools liblockdep
like the way other stuff under tools/ can be built

Signed-off-by: S. Lockwood-Childs <[e-mail]>
Signed-off-by: Sasha Levin <[e-mail]>

tools/Makefile

···
 cgroup firewire hv guest usb virtio vm net: FORCE
 	$(call descend,$@)
 
+liblockdep: FORCE
+	$(call descend,lib/lockdep)
+
 libapikfs: FORCE
 	$(call descend,lib/api)
 
···
 
 cgroup_clean hv_clean firewire_clean lguest_clean usb_clean virtio_clean vm_clean net_clean:
 	$(call descend,$(@:_clean=),clean)
+
+liblockdep_clean:
+	$(call descend,lib/lockdep,clean)
 
 libapikfs_clean:
 	$(call descend,lib/api,clean)

tools/lib/lockdep/Makefile

···
 # file format version
 FILE_VERSION = 1
 
-MAKEFLAGS += --no-print-directory
-LIBLOCKDEP_VERSION=$(shell make -sC ../../.. kernelversion)
+LIBLOCKDEP_VERSION=$(shell make --no-print-directory -sC ../../.. kernelversion)
 
 # Makefiles suck: This macro sets a default value of $(2) for the
 # variable named by $(1), unless the variable has been set by