PM: sleep: Remove unnecessary !!

Since initcall_debug is a bool variable, it is not necessary to convert
it to bool with the help of a double logical negation (!!).

Remove the redundant operation.

Signed-off-by: Zihuan Zhang <zhangzihuan@kylinos.cn>
Link: https://patch.msgid.link/20250424060339.73119-1-zhangzihuan@kylinos.cn


[ rjw: Changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>