ext4: stop trying to verify just initialized bitmap in ext4_read_block_bitmap_nowait

ext4: stop trying to verify just initialized bitmap in ext4_read_block_bitmap_nowait

For case we initialize a bitmap bh, we will set bitmap bh verified.
We can return immediately instead of goto verify to remove unnecessary
work for trying to verify bitmap bh.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230221115919.1918161-7-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>