builtin-apply: fix typo leading to stack corruption
builtin-apply: fix typo leading to stack corruption

This typo led to stack corruption for lines with whitespace fixes
and length > 1024.

Signed-off-by: Imre Deak <fbd5edba1988036c8923f0cca0cce6ac4811db29@gmail.com>
Looks-good-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>
Signed-off-by: Shawn O. Pearce <f01032651c12a22b2103346ba96b3b6b231f9d3c@spearce.org>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git