Fix delegation states from flags to state values!

They are not really flags, so fix the macros to use consecutive intergers.

Should we use enum? Also, any suggestions to squash (or not suqash) the
following two more commits into this one?

Signed-off-by: Malahal Naineni <malahal@us.ibm.com>
Remove unused DELEG_REVOKED macro definition

Signed-off-by: Malahal Naineni <malahal@us.ibm.com>
Remove unneeded DELEG_RETURNED state

Delegation state DELEG_RETURNED is set when the state_t is about to be
deleted. This isn't needed, and removed DELEG_RETURNED macro as well.

Signed-off-by: Malahal Naineni <malahal@us.ibm.com>