firmware loader: allow builtin firmware load even if usermodehelper is disabled

In commit a144c6a6c924 ("PM: Print a warning if firmware is requested
when tasks are frozen") we not only printed a warning if somebody tried
to load the firmware when tasks are frozen - we also failed the load.

But that check was done before the check for built-in firmware, and then
when we disallowed usermode helpers during bootup (commit 288d5abec831:
"Boot up with usermodehelper disabled"), that actually means that
built-in modules can no longer load their firmware even if the firmware
is built in too. Which used to work, and some people depended on it for
the R100 driver.

So move the test for usermodehelper_is_disabled() down, to after
checking the built-in firmware.

This should fix:

https://bugzilla.kernel.org/show_bug.cgi?id=40952

Reported-by: James Cloos <[e-mail]>
Bisected-by: Elimar Riesebieter <[e-mail]>
Cc: Michel Dänzer <[e-mail]>
Cc: Rafael Wysocki <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Valdis Kletnieks <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/base/firmware_class.c

···
 	if (!firmware_p)
 		return -EINVAL;
 
-	if (WARN_ON(usermodehelper_is_disabled())) {
-		dev_err(device, "firmware: %s will not be loaded\n", name);
-		return -EBUSY;
-	}
-
 	*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
 	if (!firmware) {
 		dev_err(device, "%s: kmalloc(struct firmware) failed\n",
···
 	if (fw_get_builtin_firmware(firmware, name)) {
 		dev_dbg(device, "firmware: using built-in firmware %s\n", name);
 		return 0;
+	}
+
+	if (WARN_ON(usermodehelper_is_disabled())) {
+		dev_err(device, "firmware: %s will not be loaded\n", name);
+		retval = -EBUSY;
+		goto out;
 	}
 
 	if (uevent)