explicitly detach loop device on umount and silent losetup error

Umount detaches the loop device automatically, but let's make it
explicit to be sure. Additionally losetup gives:

losetup: /dev/loop0: detach failed: No such device or address

This is kind of expected, let's silent the error message.

Signed-off-by: Christian Hesse <mail@eworm.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/hooks/archiso b/hooks/archiso
index fcfe820..23459e7 100644
--- a/hooks/archiso
+++ b/hooks/archiso
@@ -182,7 +182,7 @@ archiso_mount_handler() {
     fi
 
     if [[ "${copytoram}" == "y" ]]; then
-        umount /run/archiso/bootmnt
+        umount -d /run/archiso/bootmnt
     fi
 }