Ubuntu: (Multiple Advisories) (CVE-2024-26894): Linux kernel vulnerabilities

In the Linux kernel, the following vulnerability has been resolved:

ACPI: processor_idle: Fix memory leak in acpi_processor_power_exit()

After unregistering the CPU idle device, the memory associated with
it is not freed, leading to a memory leak:

unreferenced object 0xffff896282f6c000 (size 1024):
comm "swapper/0", pid 1, jiffies 4294893170
hex dump (first 32 bytes):
00 00 00 00 0b 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 8836a742):
[] kmalloc_trace+0x29d/0x340
[] acpi_processor_power_init+0xf3/0x1c0
[] __acpi_processor_start+0xd3/0xf0
[] acpi_processor_start+0x2c/0x50
[] really_probe+0xe2/0x480
[] __driver_probe_device+0x78/0x160
[] driver_probe_device+0x1f/0x90
[] __driver_attach+0xce/0x1c0
[] bus_for_each_dev+0x70/0xc0
[] bus_add_driver+0x112/0x210
[] driver_register+0x55/0x100
[] acpi_processor_driver_init+0x3b/0xc0
[] do_one_initcall+0x41/0x300
[] kernel_init_freeable+0x320/0x470
[] kernel_init+0x16/0x1b0
[] ret_from_fork+0x2d/0x50

Fix this by freeing the CPU idle device after unregistering it.