ocfs2: optimize bad declarations and redundant assignment

In ocfs2_parse_options,

a) it's better to declare variables(small size) outside of while loop;

b) 'option' will be set by match_int, 'option = 0;' makes no sense, if
   match_int failed, it just goto bail and return.

Signed-off-by: Norton.Zhu <norton.zhu@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Gang He <ghe@suse.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Acked-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>