Fix `if_not_else` lint #2601

Job	Run time
msrv	49s
minimal	17s
quickchecking	20s
rustfmt-clippy	26s
check-cfg	20s
docs	30s
test (ubuntu-latest, 9.0, 1, 0, 0, 0, 0)	1m 54s
test-book	7s
test (ubuntu-latest, 9.0, 1, 0, 0, 1, 0)	1m 51s
test-expectations (ubuntu-latest)	50s
test (ubuntu-latest, 9.0, 1, 0, 1, 0, 0)	1m 43s
test-expectations (macos-12)	1m 1s
test (ubuntu-latest, 9.0, 1, 0, 1, 1, 0)	1m 46s
test (ubuntu-latest, 9.0, 1, 1, 0, 0, 0)	2m 21s
test (ubuntu-latest, 9.0, 1, 1, 0, 1, 0)	2m 15s
test (ubuntu-latest, 9.0, 1, 1, 1, 0, 0)	2m 23s
test (ubuntu-latest, 9.0, 1, 1, 1, 1, 0)	2m 11s
test (ubuntu-latest, 16.0, 1, 0, 0, 0, 0)	4m 5s
test (ubuntu-latest, 16.0, 1, 0, 0, 1, 0)	4m 4s
test (ubuntu-latest, 16.0, 1, 0, 1, 0, 0)	3m 58s
test (ubuntu-latest, 16.0, 1, 0, 1, 1, 0)	4m 7s
test (ubuntu-latest, 16.0, 1, 1, 0, 0, 0)	5m 24s
test (ubuntu-latest, 16.0, 1, 1, 0, 1, 0)	4m 51s
test (ubuntu-latest, 16.0, 1, 1, 1, 0, 0)	4m 51s
test (ubuntu-latest, 16.0, 1, 1, 1, 1, 0)	4m 57s
test (ubuntu-latest, 16.0, 0, 0, 1)	1m 44s
test (macos-12, 9.0, 0, 0, 0)	1m 47s
success	1s
	1h 0m 53s

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