ext4: mark inode bitmap corrupted when found

There are still some cases that we missed to set
block bitmaps corrupted bit properly:

1)inode bitmap number is wrong.
2)failed to read block bitmap due to disk errors.
3)double allocations from bitmap

Also remove a duplicated call ext4_error() afer
ext4_read_inode_bitmap(), as ext4_error() have been
called inside ext4_read_inode_bitmap() properly.

Signed-off-by: Wang Shilong <wshilong@ddn.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>