The argument chain for ext[234]_find_goal() is not used.  This patch removes
it and fixes comment as well.

Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>