visorbus: fix error return code in visorchipset_init()

BugLink: https://bugs.launchpad.net/bugs/1938199

[ Upstream commit ce52ec5 ]

Commit 1366a3d ("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 f1f537c ("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: f1f537c ("staging: unisys: visorbus: Consolidate controlvm channel creation.")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20210528082614.9337-1-thunder.leizhen@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

Author: Zhen Lei

drivers/visorbus/visorchipset.c

@@ -1561,7 +1561,7 @@ static void controlvm_periodic_work(struct work_struct *work)
 
 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);
@@ -1584,8 +1584,10 @@ static int visorchipset_init(struct acpi_device *acpi_device)
 				 "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,