Prefer struct_size() over open-coded versions.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 include/linux/spi/spi.h | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index c9479badf38c..9fb8efb068c6 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h

@@ -17,6 +17,7 @@
 #include <linux/minmax.h>
 #include <linux/mod_devicetable.h>
 #include <linux/mutex.h>
+#include <linux/overflow.h>
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include <linux/smp.h>

@@ -1095,6 +1096,8 @@ struct spi_transfer {
  * @state: for use by whichever driver currently owns the message
  * @resources: for resource management when the spi message is processed
  * @prepared: spi_prepare_message was called for the this message
+ * @t: for use with spi_message_alloc() when message and transfers have
+ *	been allocated together
  *
  * A @spi_message is used to execute an atomic sequence of data transfers,
  * each represented by a struct spi_transfer.  The sequence is "atomic"

@@ -1147,6 +1150,9 @@ struct spi_message {
 
 	/* List of spi_res reources when the spi message is processed */
 	struct list_head        resources;
+
+	/* For embedding transfers into the memory of the message */
+	struct spi_transfer	t[];