Fix label on /dev/input

Commit 780a71e7 changed ueventd's selinux label lookup from /dev/input/
to /dev/input which no longer matches the regex in core policy
file_contexts. Fix the regex to match /dev/input and /dev/input/.

avc: denied { read } for name="input" dev="tmpfs" ino=14092
scontext=u:r:hal_camera_default:s0 tcontext=u:object_r:device:s0
tclass=dir
avc: denied { open } for path="/dev/input" dev="tmpfs"
ino=14092 scontext=u:r:hal_camera_default:s0
tcontext=u:object_r:device:s0 tclass=dir

Change-Id: I8f42f5cd96fc8353bf21d3ee6c3de9e2872f229f
Fixes: 64997761
Fixes: 64954704
Test: no camera HAL denials