i2c-dev: Fix typo in ioctl name reference

The ioctl is named I2C_RDWR for "I2C read/write". But references to it
were misspelled "rdrw". Fix them.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/include/uapi/linux/i2c-dev.h b/include/uapi/linux/i2c-dev.h
index 3f31155..2f05e66 100644
--- a/include/uapi/linux/i2c-dev.h
+++ b/include/uapi/linux/i2c-dev.h
@@ -66,7 +66,9 @@
 	__u32 nmsgs;			/* number of i2c_msgs */
 };
 
-#define  I2C_RDRW_IOCTL_MAX_MSGS	42
+#define  I2C_RDWR_IOCTL_MAX_MSGS	42
+/* Originally defined with a typo, keep it for compatibility */
+#define  I2C_RDRW_IOCTL_MAX_MSGS	I2C_RDWR_IOCTL_MAX_MSGS
 
 
 #endif /* _UAPI_LINUX_I2C_DEV_H */