SwKernPortion is inserted between different scripts  to
snap the later text portion to the charcter grid if type
of text grid is lines and chars, even if snap-to-char
isn't checked, and create unexpected space there.

It is not necessary because when snap-to-char is not
checked, there would be pitch between characters.

Format all three scripts in the same way and do not
insert kern portion anymore if snap-to-char isn't checked.

Change-Id: I6078b425aa735beb50cc6a6b4eafbba9f91f7132
Reviewed-on: https://gerrit.libreoffice.org/37037Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mark Hung <marklh9@gmail.com>