Linux 4.4.15

BugLink: http://bugs.launchpad.net/bugs/1601952Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

Makefile

 VERSION = 4
 PATCHLEVEL = 4
-SUBLEVEL = 14
+SUBLEVEL = 15
 EXTRAVERSION =
 NAME = Blurry Fish Butt