staging: Use GFP_ATOMIC when a lock is held

In each case, the containing function is only called from one place, where
a spin lock is held.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@gfp exists@
identifier fn;
position p;
@@

fn(...) {
... when != spin_unlock
    when any
  GFP_KERNEL@p
 ... when any
}

@locked@
identifier gfp.fn;
@@

spin_lock(...)
... when != spin_unlock
fn(...)

@depends on locked@
position gfp.p;
@@

- GFP_KERNEL@p
+ GFP_ATOMIC
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Marek Lindner <lindner_marek@yahoo.de>
Cc: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/iio/ring_sw.c b/drivers/staging/iio/ring_sw.c
index 1f14cd4..294272d 100644
--- a/drivers/staging/iio/ring_sw.c
+++ b/drivers/staging/iio/ring_sw.c
@@ -20,7 +20,7 @@
 	if ((length == 0) || (bytes_per_datum == 0))
 		return -EINVAL;
 	__iio_update_ring_buffer(&ring->buf, bytes_per_datum, length);
-	ring->data = kmalloc(length*ring->buf.bpd, GFP_KERNEL);
+	ring->data = kmalloc(length*ring->buf.bpd, GFP_ATOMIC);
 	ring->read_p = NULL;
 	ring->write_p = NULL;
 	ring->last_written_p = NULL;