firmware_class: make request_firmware_nowait more useful

Unfortunately, one cannot hold on to the struct firmware
that request_firmware_nowait() hands off, which is needed
in some cases. Allow this by requiring the callback to
free it (via release_firmware).

Additionally, give it a gfp_t parameter -- all the current
users call it from a GFP_KERNEL context so the GFP_ATOMIC
isn't necessary. This also marks an API break which is
useful in a sense, although that is obviously not the
primary purpose of this change.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Woodhouse <David.Woodhouse@intel.com>
Cc: Pavel Roskin <proski@gnu.org>
Cc: Abhay Salunke <abhay_salunke@dell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/serial/ucc_uart.c b/drivers/serial/ucc_uart.c
index 46de564..465f2fa 100644
--- a/drivers/serial/ucc_uart.c
+++ b/drivers/serial/ucc_uart.c
@@ -1179,16 +1179,18 @@
 
 	if (firmware->header.length != fw->size) {
 		dev_err(dev, "invalid firmware\n");
-		return;
+		goto out;
 	}
 
 	ret = qe_upload_firmware(firmware);
 	if (ret) {
 		dev_err(dev, "could not load firmware\n");
-		return;
+		goto out;
 	}
 
 	firmware_loaded = 1;
+ out:
+	release_firmware(fw);
 }
 
 static int ucc_uart_probe(struct of_device *ofdev,
@@ -1247,7 +1249,7 @@
 			 */
 			ret = request_firmware_nowait(THIS_MODULE,
 				FW_ACTION_HOTPLUG, filename, &ofdev->dev,
-				&ofdev->dev, uart_firmware_cont);
+				GFP_KERNEL, &ofdev->dev, uart_firmware_cont);
 			if (ret) {
 				dev_err(&ofdev->dev,
 					"could not load firmware %s\n",