label /dev/block/zram

Addresses the following denial:

  <5>[    2.823156] type=1400 audit(1437400730.635:4): avc:  denied  { read write } for  pid=153 comm="mkswap" name="zram0" dev="tmpfs" ino=12517 scontext=u:r:toolbox:s0 tcontext=u:object_r:block_device:s0 tclass=blk_file permissive=0
  <5>[    2.824263] type=1400 audit(1437400730.635:5): avc:  denied  { write } for  pid=1 comm="init" name="zram0" dev="tmpfs" ino=12517 scontext=u:r:init:s0 tcontext=u:object_r:block_device:s0 tclass=blk_file permissive=0

Bug: 22637114
Change-Id: I7f731a7af42409e5b64a315470b0497d0012d8af
diff --git a/sepolicy/file_contexts b/sepolicy/file_contexts
index 15fc03e..8b172dc 100644
--- a/sepolicy/file_contexts
+++ b/sepolicy/file_contexts
@@ -22,4 +22,5 @@
 /dev/block/pci/pci0000:00/0000:00:01\.0/by-name/cache          u:object_r:cache_block_device:s0
 /dev/block/pci/pci0000:00/0000:00:01\.0/by-name/userdata       u:object_r:userdata_block_device:s0
 /dev/block/pci/pci0000:00/0000:00:01\.0/by-name/recovery       u:object_r:recovery_block_device:s0
-/dev/block/pci/pci0000:00/0000:00:01\.0/by-name/boot           u:object_r:boot_block_device:s0
\ No newline at end of file
+/dev/block/pci/pci0000:00/0000:00:01\.0/by-name/boot           u:object_r:boot_block_device:s0
+/dev/block/zram0                                               u:object_r:swap_block_device:s0