ipmitool: Bump ipmitool to 1.8.15

New release fixes a number of bugs, including some needed for talking
to modern AMI BMC firmware as shipped on some POWER8 systems.

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/ipmitool/ipmitool.hash

@@ -1,2 +1,2 @@
 # Locally computed:
-sha256  3209c99b996fdea38c462cfd10387d6895fd5261227ab6f79b59f88e21938ce5  ipmitool-1.8.14.tar.bz2
+sha256  4acd2df5f8740fef5c032cebee0113ec4d3bbef04a6f4dbfaf7fcc7f3eb08c40  ipmitool-1.8.15.tar.bz2

package/ipmitool/ipmitool.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-IPMITOOL_VERSION = 1.8.14
+IPMITOOL_VERSION = 1.8.15
 IPMITOOL_SOURCE = ipmitool-$(IPMITOOL_VERSION).tar.bz2
 IPMITOOL_SITE = http://downloads.sourceforge.net/project/ipmitool/ipmitool/$(IPMITOOL_VERSION)
 IPMITOOL_LICENSE = BSD-3c