i2c: Shrink struct i2c_client

This shrinks the size of "struct i2c_client" by 40 bytes:

 - Substantially shrinks the string used to identify the chip type
 - The "flags" don't need to be so big
 - Removes some internal padding

It also adds kerneldoc for that struct, explaining how "name" is really a
chip type identifier; it's otherwise potentially confusing.

Because the I2C_NAME_SIZE symbol was abused for both i2c_client.name
and for i2c_adapter.name, this needed to affect i2c_adapter too.  The
adapters which used that symbol now use the more-obviously-correct
idiom of taking the size of that field.

JD: Shorten i2c_adapter.name from 50 to 48 bytes while we're here, to
avoid wasting space in padding.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/busses/scx200_acb.c b/drivers/i2c/busses/scx200_acb.c
index 0b082c5..d816ab0 100644
--- a/drivers/i2c/busses/scx200_acb.c
+++ b/drivers/i2c/busses/scx200_acb.c
@@ -441,7 +441,7 @@
 
 	adapter = &iface->adapter;
 	i2c_set_adapdata(adapter, iface);
-	snprintf(adapter->name, I2C_NAME_SIZE, "%s ACB%d", text, index);
+	snprintf(adapter->name, sizeof(adapter->name), "%s ACB%d", text, index);
 	adapter->owner = THIS_MODULE;
 	adapter->id = I2C_HW_SMBUS_SCX200;
 	adapter->algo = &scx200_acb_algorithm;