selftests: livepatch: Test atomic replace against multiple modules

Adapt the current test-livepatch.sh script to account the number of
applied livepatches and ensure that an atomic replace livepatch disables
all previously applied livepatches.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/20240603-lp-atomic-replace-v3-1-9f3b8ace5c9f@suse.com


[mbenes@suse.cz: Fixed typo in a comment.]
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>