Fix race conditions in syscall interfaces.
Fix race conditions in syscall interfaces.

Change-Id: I19b7c1fc834927eda75231b08bfaef0f9efdd8a6
Reviewed-on: http://gfwr801.rchland.ibm.com:8080/gerrit/7
Tested-by: Jenkins Server
Tested-by: Andrew J. Geissler <c46de238cd554860f0bd4010b1729f1323facd9c@us.ibm.com>
Reviewed-by: Andrew J. Geissler <c46de238cd554860f0bd4010b1729f1323facd9c@us.ibm.com>

Over-enthusiastic/hostboot,alvintpwang/hostboot,csmart/hostboot,alvintpwang/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot,open-power/hostboot,alvintpwang/hostboot,open-power/hostboot,open-power/hostboot,open-power/hostboot,csmart/hostboot,alvintpwang/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot,open-power/hostboot,csmart/hostboot,csmart/hostboot,csmart/hostboot,alvintpwang/hostboot