ext2: introduce flag argument for ext2_new_blocks()

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I7TN3J



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This patch introduce introduce flag argument for ext2_new_blocks(), and also
introduce EXT2_ALLOC_NORESERVE flags.

Signed-off-by: Ye Bin <yebin10@huawei.com>