rt2x00: rt2800: convert read_eeprom functions to return an int value

Both the rtt2x00usb_eeprom_read and the ioremap
functions are allowed to fail, however their
return values are not checked in the read_eeprom
functions in the rt2800{pci,usb} drivers.

The patch adds the missing checks, and converts
all read_eeprom functions to return an int value,
so the error values can be propagated up to the
'rt2800_validate_eeprom' function.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2800lib.h b/drivers/net/wireless/rt2x00/rt2800lib.h
index a128cea..6ec7394 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.h
+++ b/drivers/net/wireless/rt2x00/rt2800lib.h
@@ -43,7 +43,7 @@
 			    const unsigned int offset,
 			    const struct rt2x00_field32 field, u32 *reg);
 
-	void (*read_eeprom)(struct rt2x00_dev *rt2x00dev);
+	int (*read_eeprom)(struct rt2x00_dev *rt2x00dev);
 	bool (*hwcrypt_disabled)(struct rt2x00_dev *rt2x00dev);
 
 	int (*drv_write_firmware)(struct rt2x00_dev *rt2x00dev,
@@ -117,11 +117,11 @@
 	return rt2800ops->regbusy_read(rt2x00dev, offset, field, reg);
 }
 
-static inline void rt2800_read_eeprom(struct rt2x00_dev *rt2x00dev)
+static inline int rt2800_read_eeprom(struct rt2x00_dev *rt2x00dev)
 {
 	const struct rt2800_ops *rt2800ops = rt2x00dev->ops->drv;
 
-	rt2800ops->read_eeprom(rt2x00dev);
+	return rt2800ops->read_eeprom(rt2x00dev);
 }
 
 static inline bool rt2800_hwcrypt_disabled(struct rt2x00_dev *rt2x00dev)
@@ -207,7 +207,7 @@
 void rt2800_disable_radio(struct rt2x00_dev *rt2x00dev);
 
 int rt2800_efuse_detect(struct rt2x00_dev *rt2x00dev);
-void rt2800_read_eeprom_efuse(struct rt2x00_dev *rt2x00dev);
+int rt2800_read_eeprom_efuse(struct rt2x00_dev *rt2x00dev);
 
 int rt2800_probe_hw(struct rt2x00_dev *rt2x00dev);