tmf : Replace String() by an empty string "" in getHelpText

tmf : Replace String() by an empty string "" in getHelpText

Replace the creation of an empty string using new String() with ""
instead.

Change-Id: Iebbe8dfc48eb5f963dda8d196eaa57e5f32258d3
Signed-off-by: Jean-Christian Kouame <jean-christian.kouame@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/60949
Reviewed-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Tested-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Reviewed-by: Hudson CI
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>