[fix]: mkdir -r with store path, not lock path

[0x009922]

Description

TBH, I am lazy to prepare a proper reproduction of the bug. In my case, Iroha repeatedly failed to start, complaining about existence of the lock file all the time. After all, it turned out that ./storage/kura.lock, created by Iroha, is a directory, not a file.

This PR makes variables naming clearer, and passes actual block-store path into mkdir -r, not the path of the lockfile.

[coveralls]

Pull Request Test Coverage Report for Build 6259473002

• 5 of 10 (50.0%) changed or added relevant lines in 1 file are covered.
• 6113 unchanged lines in 102 files lost coverage.
• Overall coverage decreased (-1.1%) to 58.327%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
core/src/kura.rs	5	10	50.0%

Files with Coverage Reduction	New Missed Lines	%
cli/src/main.rs	1	0.0%
cli/src/torii/pagination.rs	1	98.9%
config/base/src/runtime_upgrades.rs	1	51.72%
config/src/torii.rs	1	96.67%
core/src/smartcontracts/isi/block.rs	1	87.5%
crypto/src/merkle.rs	1	96.23%
data_model/derive/src/partially_tagged.rs	1	99.67%
data_model/src/domain.rs	1	47.37%
logger/src/lib.rs	1	95.15%
config/src/lib.rs	2	0.0%

Totals
Change from base Build 5423219773:	-1.1%
Covered Lines:	21419
Relevant Lines:	36722

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💛 - Coveralls