lttng-libust: bump version to 2.4.0

Also adjust the license details

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/lttng-libust/lttng-libust.mk

@@ -5,9 +5,9 @@
 ################################################################################
 
 LTTNG_LIBUST_SITE    = http://lttng.org/files/lttng-ust/
-LTTNG_LIBUST_VERSION = 2.2.0
+LTTNG_LIBUST_VERSION = 2.4.0
 LTTNG_LIBUST_SOURCE  = lttng-ust-$(LTTNG_LIBUST_VERSION).tar.bz2
-LTTNG_LIBUST_LICENSE = LGPLv2.1; GPLv2 for lttng-gen-tp and ust-ctl
+LTTNG_LIBUST_LICENSE = LGPLv2.1; MIT for system headers; GPLv2 for liblttng-ust-ctl/ustctl.c (used by lttng-sessiond)
 LTTNG_LIBUST_LICENSE_FILES = COPYING
 
 LTTNG_LIBUST_INSTALL_STAGING = YES