livepatch: Add a missing newline character in klp_module_coming()

The error message is not printed immediately because it does not end with
a newline character.

Before:
root@localhost:~# insmod vmlinux.ko
insmod: ERROR: could not insert module vmlinux.ko: Invalid parameters

After:
root@localhost:~# insmod vmlinux.ko
[   43.982558] livepatch: vmlinux.ko: invalid module name
insmod: ERROR: could not insert module vmlinux.ko: Invalid parameters

Fixes: dcf550e5 ("livepatch: Disallow vmlinux.ko")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220830112855.749-1-thunder.leizhen@huawei.com