Allow init to create /mnt/sdcard symlink.

Addresses the following denial:
avc:  denied  { create } for  pid=1 comm="init" name="sdcard" scontext=u:r:init:s0 tcontext=u:object_r:tmpfs:s0 tclass=lnk_file permissive=0

Bug: 22084499
Change-Id: Icffef8330d07b00f36fda11374e39e0df7181ca3
diff --git a/sepolicy/init.te b/sepolicy/init.te
index 14f1b92..33cbf02 100644
--- a/sepolicy/init.te
+++ b/sepolicy/init.te
@@ -1 +1,2 @@
 allow init diag_device:chr_file unlink;
+allow init tmpfs:lnk_file create_file_perms;