fs: Fix syntax issues in comments and print statements.

hulk inclusion
category: cleanup
bugzilla: https://gitee.com/openeuler/kernel/issues/I8HWD1



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There are syntax errors in the comments and print statements of the code
section that detects opening write opened block devices exclusively,
which need to be fixed.

Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>