Fix bugs in copyright prolog script
Fix bugs in copyright prolog script

Add exists check to if statment
Made sure current commiter is added to changes

Change-Id: I1fa6f85827598cf2c755d1ded4610997ee8847c7
Reviewed-on: http://gfw160.aus.stglabs.ibm.com:8080/gerrit/11890
Reviewed-by: Brian Silver <af0eed78d989d9597decc8b92fa6db01ef8b58e0@us.ibm.com>
Tested-by: Jenkins Server
Reviewed-by: A. Patrick Williams III <c87e37b1a4035affd737b461af89fb722d635f4d@us.ibm.com>

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