apparmor: fix memleak of the profile hash

apparmor: fix memleak of the profile hash

BugLink: http://bugs.launchpad.net/bugs/1235523
This fixes the following kmemleak trace:
unreferenced object 0xffff8801e8c35680 (size 32):
  comm "apparmor_parser", pid 691, jiffies 4294895667 (age 13230.876s)
  hex dump (first 32 bytes):
    e0 d3 4e b5 ac 6d f4 ed 3f cb ee 48 1c fd 40 cf  ..N..m..?..H..@.
    5b cc e9 93 00 00 00 00 00 00 00 00 00 00 00 00  [...............
  backtrace:
    [<ffffffff817a97ee>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff811ca9f3>] __kmalloc+0x103/0x290
    [<ffffffff8138acbc>] aa_calc_profile_hash+0x6c/0x150
    [<ffffffff8138074d>] aa_unpack+0x39d/0xd50
    [<ffffffff8137eced>] aa_replace_profiles+0x3d/0xd80
    [<ffffffff81376937>] profile_replace+0x37/0x50
    [<ffffffff811e9f2d>] vfs_write+0xbd/0x1e0
    [<ffffffff811ea96c>] SyS_write+0x4c/0xa0
    [<ffffffff817ccb1d>] system_call_fastpath+0x1a/0x1f
    [<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>