Fix `map_unwrap_or` lint #2600

Job	Run time
minimal	16s
check-cfg	25s
docs	26s
msrv	49s
quickchecking	20s
rustfmt-clippy	29s
test (ubuntu-latest, 9.0, 1, 0, 0, 0, 0)	2m 0s
test-book	5s
test (ubuntu-latest, 9.0, 1, 0, 0, 1, 0)	1m 46s
test-expectations (ubuntu-latest)	53s
test (ubuntu-latest, 9.0, 1, 0, 1, 0, 0)	1m 50s
test-expectations (macos-12)	1m 2s
test (ubuntu-latest, 9.0, 1, 0, 1, 1, 0)	2m 3s
test (ubuntu-latest, 9.0, 1, 1, 0, 0, 0)	2m 15s
test (ubuntu-latest, 9.0, 1, 1, 0, 1, 0)	2m 22s
test (ubuntu-latest, 9.0, 1, 1, 1, 0, 0)	2m 20s
test (ubuntu-latest, 9.0, 1, 1, 1, 1, 0)	2m 26s
test (ubuntu-latest, 16.0, 1, 0, 0, 0, 0)	4m 5s
test (ubuntu-latest, 16.0, 1, 0, 0, 1, 0)	4m 3s
test (ubuntu-latest, 16.0, 1, 0, 1, 0, 0)	3m 59s
test (ubuntu-latest, 16.0, 1, 0, 1, 1, 0)	4m 38s
test (ubuntu-latest, 16.0, 1, 1, 0, 0, 0)	4m 57s
test (ubuntu-latest, 16.0, 1, 1, 0, 1, 0)	5m 14s
test (ubuntu-latest, 16.0, 1, 1, 1, 0, 0)	4m 43s
test (ubuntu-latest, 16.0, 1, 1, 1, 1, 0)	5m 22s
test (ubuntu-latest, 16.0, 0, 0, 1)	1m 45s
test (macos-12, 9.0, 0, 0, 0)	1m 56s
success	1s
	1h 2m 30s

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