Bug fix on installd with SELinux enabled kernel.

setfilecon is not required on libsymlinks when target
doesn't exist. A bootloop is caused without this
change.

Change-Id: I96dbd4b1f47a752bfcaf6016c81fd43083c4a6e1
Signed-off-by: rpcraig <rpcraig@tycho.ncsc.mil>