PMem: fix c++11 narrowing for legacy PMem

The best fix for these narrowing
violations is to use static casting

Change-Id: I900b1ebb658fc9afbfbb4943faecce9d772285ac
Signed-off-by: DHOMD <DHO@dho.im>
binder: fix c++11 narrowing violations

Summary:
The best fix for these narrowing
violations is to use static casting

Test Plan: verified

Reviewers: randall.rushing, synergy

Reviewed By: synergy

Differential Revision: http://review.codefirex.com/D85

Change-Id: I7717f7b09b75167a7db979fef7212e00d0541051
Signed-off-by: DHOMD <DHO@dho.im>