Trailing whitespace and no newline fix

Trailing whitespace and no newline fix

If a patch adds a new line to the end of a file and this line ends with
one trailing whitespace character and has no newline, then
'--whitespace=fix' currently does not remove that trailing whitespace.

This patch fixes this by removing the check for trailing whitespace at
the end of the line at a hardcoded offset which does not take the
eventual absence of newline into account.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>