[PATCH v2] counter: fix an IS_ERR() vs NULL bug

[Dan Carpenter <dan.carpenter@oracle.com>]

There are 8 callers for devm_counter_alloc() and they all check for NULL
instead of error pointers.  I think NULL is the better thing to return
for allocation functions so update counter_alloc() and devm_counter_alloc()
to return NULL instead of error pointers.

Fixes: c18e2760308e ("counter: Provide alternative counter registration functions")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: make additional style changes

 drivers/counter/counter-core.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c
index 7e0957eea094..869894b74741 100644
--- a/drivers/counter/counter-core.c
+++ b/drivers/counter/counter-core.c
@@ -90,10 +90,8 @@ struct counter_device *counter_alloc(size_t sizeof_priv)
 	int err;
 
 	ch = kzalloc(sizeof(*ch) + sizeof_priv, GFP_KERNEL);
-	if (!ch) {
-		err = -ENOMEM;
-		goto err_alloc_ch;
-	}
+	if (!ch)
+		return NULL;
 
 	counter = &ch->counter;
 	dev = &counter->dev;
@@ -123,9 +121,8 @@ struct counter_device *counter_alloc(size_t sizeof_priv)
 err_ida_alloc:
 
 	kfree(ch);
-err_alloc_ch:
 
-	return ERR_PTR(err);
+	return NULL;
 }
 EXPORT_SYMBOL_GPL(counter_alloc);
 
@@ -208,12 +205,12 @@ struct counter_device *devm_counter_alloc(struct device *dev, size_t sizeof_priv
 	int err;
 
 	counter = counter_alloc(sizeof_priv);
-	if (IS_ERR(counter))
-		return counter;
+	if (!counter)
+		return NULL;
 
 	err = devm_add_action_or_reset(dev, devm_counter_put, counter);
 	if (err < 0)
-		return ERR_PTR(err);
+		return NULL;
 
 	return counter;
 }
-- 
2.20.1