ocfs2: fix shift left operations overflow

ocfs2_inode_info->ip_clusters and ocfs2_dinode->id1.bitmap1.i_total are
defined as type u32, so the shift left operations may overflow if volume
size is large, for example, 2TB and cluster size is 1MB.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Alex Chen <alex.chen@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>