lvm2: prevent dmsetup from being re-installed every time

After being copied to target/, touch dmsetup so that its date is newer
than the .built stamp file in lvm2 source directory. This prevents
make from re-installing dmsetup every time.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/lvm2/lvm2.mk

@@ -86,9 +86,11 @@ $(LVM2_DIR)/.built: $(LVM2_DIR)/.configured
 
 $(LVM2_TARGET_SBINS) $(LVM2_TARGET_DMSETUP_SBINS): $(LVM2_DIR)/.built
 	cp -a $(STAGING_DIR)/sbin/$(notdir $@) $@
+	touch $@
 
 $(LVM2_TARGET_LIBS): $(LVM2_DIR)/.built
 	cp -a $(STAGING_DIR)/lib/$(notdir $@) $@
+	touch $@
 
 
 ifeq ($(BR2_PACKAGE_LVM2_DMSETUP_ONLY),y)