udf: fix sparse warning in namei.c

Let's use bsize instead.
fs/udf/namei.c:960:12: warning: symbol 'elen' shadows an earlier one
fs/udf/namei.c:937:15: originally declared here

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>