IMPALA-2125: Make UTC to local TimestampValue conversion faster.
IMPALA-2125: 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
(cherry picked from commit 29de99c9d25c49b73488d2f75bc3644ae9ff9325)

scalingdata/Impala,scalingdata/Impala,scalingdata/Impala,scalingdata/Impala,scalingdata/Impala,scalingdata/Impala