[PATCH] acpi: avoid uninialized-variable warning

[Arnd Bergmann <arnd@arndb.de>]

Older compilers like gcc-4.8 produce a bogus warning here

In file included from include/linux/compiler_types.h:68:0,
                 from <command-line>:0:
drivers/acpi/property.c: In function 'acpi_data_prop_read':
include/linux/compiler-gcc.h:75:45: error: 'obj' may be used uninitialized in this function [-Werror=maybe-uninitialized]
 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
                                             ^
drivers/acpi/property.c:934:27: note: 'obj' was declared here
  const union acpi_object *obj;
                           ^

Ensure the output is always initialized even when returning an error
to avoid the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/acpi/property.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index e601c4511a8b..3aa71daeb0b4 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -587,8 +587,10 @@ static int acpi_data_get_property_array(const struct acpi_device_data *data,
 	int ret, i;
 
 	ret = acpi_data_get_property(data, name, ACPI_TYPE_PACKAGE, &prop);
-	if (ret)
+	if (ret && obj) {
+		*obj = NULL;
 		return ret;
+	}
 
 	if (type != ACPI_TYPE_ANY) {
 		/* Check that all elements are of correct type. */
-- 
2.26.0