Drivers: hv: mshv_vtl: remove duplicate misc_deregister() in module exit

mshv_vtl_exit() calls misc_deregister(&mshv_vtl_sint_dev) and
misc_deregister(&mshv_vtl_low) twice. The first pair (added when the
TDX APIC handling code was introduced) is redundant: the same
deregistrations are performed again a few lines below, in the order
that mirrors the registration sequence in mshv_vtl_init().

Calling misc_deregister() twice on the same struct miscdevice is not
safe -- it ends up doing list_del() twice on the device's misc_list
node, corrupting the global list and yielding 'list_del corruption'
splats on rmmod (or any module exit path).

Drop the redundant calls so each device is deregistered exactly once,
in the reverse order of registration.

Fixes: 06eb1e3 ("mshv_vtl/tdx: Handle some APIC functionality in kernel")
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>

Author: Naman Jain

drivers/hv/mshv_vtl_main.c

@@ -4098,8 +4098,6 @@ static void __exit mshv_vtl_exit(void)
 
 	ms_hyperv_free_redirected_intr();
 	mshv_free_apicid_to_cpuid_mapping();
-	misc_deregister(&mshv_vtl_sint_dev);
-	misc_deregister(&mshv_vtl_low);
 	device_del(mem_dev);
 	kfree(mem_dev);
 	mshv_vtl_sidecar_exit();