f2fs: add testcase to check resize corrupting root inode

f2fs: add testcase to check resize corrupting root inode

This is a regression test to check whether the f2fs root inode
is corrupted after the resize operation.
During the resize operation, SSA data blocks are migrated and
zeroed. This process may incorrectly zero out the main area
blocks, leading to root inode corruption.

Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Signed-off-by: Yangyang Zang <zangyangyang1@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Zorro Lang <zlang@kernel.org>