s390x-se-luks-gencpio: Fix shebang syntax

An indented `#!` is technically meaningless, although many shells will
run text files with the shell if asked to execute them.

Signed-off-by: Simon McVittie <smcv@debian.org>

src/libostree/s390x-se-luks-gencpio

@@ -1,5 +1,5 @@
- #!/usr/bin/bash
+#!/usr/bin/bash
- # This script creates new initramdisk with LUKS config within
+# This script creates new initramdisk with LUKS config within
 set -euo pipefail
 
 old_initrd=$1