memstick: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/memstick/core/memstick.c b/drivers/memstick/core/memstick.c
index 56ff19c..ffcb10a 100644
--- a/drivers/memstick/core/memstick.c
+++ b/drivers/memstick/core/memstick.c
@@ -512,18 +512,17 @@
 {
 	int rc;
 
-	while (1) {
-		if (!idr_pre_get(&memstick_host_idr, GFP_KERNEL))
-			return -ENOMEM;
+	idr_preload(GFP_KERNEL);
+	spin_lock(&memstick_host_lock);
 
-		spin_lock(&memstick_host_lock);
-		rc = idr_get_new(&memstick_host_idr, host, &host->id);
-		spin_unlock(&memstick_host_lock);
-		if (!rc)
-			break;
-		else if (rc != -EAGAIN)
-			return rc;
-	}
+	rc = idr_alloc(&memstick_host_idr, host, 0, 0, GFP_NOWAIT);
+	if (rc >= 0)
+		host->id = rc;
+
+	spin_unlock(&memstick_host_lock);
+	idr_preload_end();
+	if (rc < 0)
+		return rc;
 
 	dev_set_name(&host->dev, "memstick%u", host->id);