drm-shim: fix EOF case

Close input end of the pipe after data was written. Without this
fix I have seen a hang in sysfs_uevent_get(.., "OF_FULLNAME")
when key was not found.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
1 file changed