gpio: convert to idr_alloc()

Convert to the much saner new idr interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpio/gpiolib.c

@@ -411,15 +411,10 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
 			goto err_out;
 		}
 
-		do {
-			ret = -ENOMEM;
-			if (idr_pre_get(&dirent_idr, GFP_KERNEL))
-				ret = idr_get_new_above(&dirent_idr, value_sd,
-							1, &id);
-		} while (ret == -EAGAIN);
-
-		if (ret)
+		ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL);
+		if (ret < 0)
 			goto free_sd;
+		id = ret;
 
 		desc->flags &= GPIO_FLAGS_MASK;
 		desc->flags |= (unsigned long)id << ID_SHIFT;