iio: Un-inline iio_buffer_enabled()

As we are going to hide the currentmode inside the opaque structure,
this helper would soon need to call a non-inline function which would
simply drop the benefit of having the helper defined inline in a header.

One alternative is to move this helper in the core as there is no more
interest in defining it inline in a header. We will pay the minor cost
either way.

Let's do like the iio_device_id() helper which also refers to the opaque
structure and gets defined in the core.
Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220207143840.707510-10-miquel.raynal@bootlin.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/industrialio-core.c

@@ -184,6 +184,18 @@ int iio_device_id(struct iio_dev *indio_dev)
 }
 EXPORT_SYMBOL_GPL(iio_device_id);
 
+/**
+ * iio_buffer_enabled() - helper function to test if the buffer is enabled
+ * @indio_dev:		IIO device structure for device
+ */
+bool iio_buffer_enabled(struct iio_dev *indio_dev)
+{
+	return indio_dev->currentmode
+		& (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE |
+		   INDIO_BUFFER_SOFTWARE);
+}
+EXPORT_SYMBOL_GPL(iio_buffer_enabled);
+
 /**
  * iio_sysfs_match_string_with_gaps - matches given string in an array with gaps
  * @array: array of strings

include/linux/iio/iio.h

@@ -550,6 +550,7 @@ struct iio_dev {
 };
 
 int iio_device_id(struct iio_dev *indio_dev);
+bool iio_buffer_enabled(struct iio_dev *indio_dev);
 
 const struct iio_chan_spec
 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si);
@@ -679,16 +680,6 @@ struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv);
 __printf(2, 3)
 struct iio_trigger *devm_iio_trigger_alloc(struct device *parent,
 					   const char *fmt, ...);
-/**
- * iio_buffer_enabled() - helper function to test if the buffer is enabled
- * @indio_dev:		IIO device structure for device
- **/
-static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
-{
-	return indio_dev->currentmode
-		& (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE |
-		   INDIO_BUFFER_SOFTWARE);
-}
 
 /**
  * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry