i2c-stub: Expose the default functionality flags

It is easier to adjust the flags when you know their default value.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
diff --git a/drivers/i2c/busses/i2c-stub.c b/drivers/i2c/busses/i2c-stub.c
index 0c770ea..b1b34479 100644
--- a/drivers/i2c/busses/i2c-stub.c
+++ b/drivers/i2c/busses/i2c-stub.c
@@ -29,13 +29,16 @@
 #include <linux/i2c.h>
 
 #define MAX_CHIPS 10
+#define STUB_FUNC (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | \
+		   I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | \
+		   I2C_FUNC_SMBUS_I2C_BLOCK)
 
 static unsigned short chip_addr[MAX_CHIPS];
 module_param_array(chip_addr, ushort, NULL, S_IRUGO);
 MODULE_PARM_DESC(chip_addr,
 		 "Chip addresses (up to 10, between 0x03 and 0x77)");
 
-static unsigned long functionality = ~0UL;
+static unsigned long functionality = STUB_FUNC;
 module_param(functionality, ulong, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(functionality, "Override functionality bitfield");
 
@@ -156,9 +159,7 @@
 
 static u32 stub_func(struct i2c_adapter *adapter)
 {
-	return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
-		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
-		I2C_FUNC_SMBUS_I2C_BLOCK) & functionality;
+	return STUB_FUNC & functionality;
 }
 
 static const struct i2c_algorithm smbus_algorithm = {