[PATCH v2 2/2] staging: nvec: fix unconditional pm_power_off teardown

[Alexandru Hossu <hossu.alexandru@gmail.com>]

tegra_nvec_remove() unconditionally sets pm_power_off = NULL, even if
nvec was not the one that registered it. This breaks any other driver
that may have set pm_power_off to its own handler.

Replace the unconditional assignment with a guarded check so that
pm_power_off is only cleared if nvec was the one that set it.

Also remove the stale FIXME comment, as the guard addresses exactly
what it was asking for.

Fixes: 3f8d52ba1c49 ("staging: nvec: Remove nvec_power module")
Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
---
v2:
 - Drop nvec_power_handle = NULL; after pm_power_off = NULL is set,
   nvec_power_off() is unreachable via pm_power_off, so there is no
   dangling-pointer risk there (Dan Carpenter)

 drivers/staging/nvec/nvec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c
index 2a3499dd4d63..88c416ee0381 100644
--- a/drivers/staging/nvec/nvec.c
+++ b/drivers/staging/nvec/nvec.c
@@ -906,8 +906,8 @@ static void tegra_nvec_remove(struct platform_device *pdev)
 	nvec_unregister_notifier(nvec, &nvec->nvec_status_notifier);
 	cancel_work_sync(&nvec->rx_work);
 	cancel_work_sync(&nvec->tx_work);
-	/* FIXME: needs check whether nvec is responsible for power off */
-	pm_power_off = NULL;
+	if (pm_power_off == nvec_power_off)
+		pm_power_off = NULL;
 }
 
 #ifdef CONFIG_PM_SLEEP
-- 
2.53.0