apply --whitespace=error: correctly report new blank lines at end

apply --whitespace=error: correctly report new blank lines at end

Earlier, 77b15bb (apply --whitespace=warn/error: diagnose blank at EOF,
2009-09-03) cheated by reporting the line number of the hunk that contains
the offending line that adds new blank lines at the end of the file. All
other types of whitespace errors are reported with the line number in the
patch file that has the actual offending text.

Signed-off-by: Junio C Hamano <gitster@pobox.com>