Make UTC to local TimestampValue conversion faster
Make UTC to local TimestampValue conversion faster

By removing a few of function calls the conversion time is reduced by
~50%.

Change-Id: Ibb18a0c646bf0a901fb5de8211a446b60634c6b0
Reviewed-on: http://gerrit.cloudera.org:8080/59
Reviewed-by: Casey Ching <77bc9a9984e6786c5799d7a71768cf023120ef76@cloudera.com>
Tested-by: Internal Jenkins

ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC