misc/tifm_core: convert to idr_alloc()

Convert to the much saner new idr interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/misc/tifm_core.c

@@ -196,13 +196,14 @@ int tifm_add_adapter(struct tifm_adapter *fm)
 {
 	int rc;
 
-	if (!idr_pre_get(&tifm_adapter_idr, GFP_KERNEL))
-		return -ENOMEM;
-
+	idr_preload(GFP_KERNEL);
 	spin_lock(&tifm_adapter_lock);
-	rc = idr_get_new(&tifm_adapter_idr, fm, &fm->id);
+	rc = idr_alloc(&tifm_adapter_idr, fm, 0, 0, GFP_NOWAIT);
+	if (rc >= 0)
+		fm->id = rc;
 	spin_unlock(&tifm_adapter_lock);
-	if (rc)
+	idr_preload_end();
+	if (rc < 0)
 		return rc;
 
 	dev_set_name(&fm->dev, "tifm%u", fm->id);