visorbus: fix error return code in visorchipset_init()

Commit 1366a3db3dcf ("staging: unisys: visorbus: visorchipset_init clean
up gotos") assigns the initial value -ENODEV to the local variable 'err',
and the first several error branches will return this value after "goto
error". But commit f1f537c2e7f5 ("staging: unisys: visorbus: Consolidate
controlvm channel creation.") overwrites 'err' in the middle of the way.
As a result, some error branches do not successfully return the initial
value -ENODEV of 'err', but return 0.

In addition, when kzalloc() fails, -ENOMEM should be returned instead of
-ENODEV.

Fixes: f1f537c2e7f5 ("staging: unisys: visorbus: Consolidate controlvm channel creation.")
Reported-by: Hulk Robot <[e-mail]>
Signed-off-by: Zhen Lei <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/visorbus/visorchipset.c

···
 
 static int visorchipset_init(struct acpi_device *acpi_device)
 {
-	int err = -ENODEV;
+	int err = -ENOMEM;
 	struct visorchannel *controlvm_channel;
 
 	chipset_dev = kzalloc(sizeof(*chipset_dev), GFP_KERNEL);
···
 				 "controlvm",
 				 sizeof(struct visor_controlvm_channel),
 				 VISOR_CONTROLVM_CHANNEL_VERSIONID,
-				 VISOR_CHANNEL_SIGNATURE))
+				 VISOR_CHANNEL_SIGNATURE)) {
+		err = -ENODEV;
 		goto error_delete_groups;
+	}
 	/* if booting in a crash kernel */
 	if (is_kdump_kernel())
 		INIT_DELAYED_WORK(&chipset_dev->periodic_controlvm_work,