all: simplify switches

[cristaloleg]

Again, some simplifications from go-critic's team 🖐
Linter's log:

check-package: $GOPATH/src/github.com/ethereum/go-ethereum/p2p/simulations/adapters/inproc.go:356:2: singleCaseSwitch: should rewrite switch statement to if statement
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/core/blockchain_test.go:1149:3: singleCaseSwitch: should rewrite switch statement to if statement
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/les/handler.go:1161:2: singleCaseSwitch: should rewrite switch statement to if statement
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/eth/tracers/tracer.go:490:2: singleCaseSwitch: found switch with default case only
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/eth/handler.go:747:3: singleCaseSwitch: should rewrite switch statement to if statement
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/p2p/nat/natpmp.go:118:4: singleCaseSwitch: should rewrite switch statement to if statement
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/p2p/nat/natupnp.go:84:4: singleCaseSwitch: should rewrite switch statement to if statement
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/eth/filters/filter_system.go:341:3: singleCaseSwitch: should rewrite switch statement to if statement
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/metrics/exp/exp.go:150:3: typeSwitchVar: case 0 can benefit from type switch with assignment
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/metrics/exp/exp.go:150:3: typeSwitchVar: case 1 can benefit from type switch with assignment
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/metrics/exp/exp.go:150:3: typeSwitchVar: case 2 can benefit from type switch with assignment
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/metrics/exp/exp.go:150:3: typeSwitchVar: case 3 can benefit from type switch with assignment
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/metrics/exp/exp.go:150:3: typeSwitchVar: case 4 can benefit from type switch with assignment
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/metrics/exp/exp.go:150:3: typeSwitchVar: case 5 can benefit from type switch with assignment
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/metrics/exp/exp.go:150:3: typeSwitchVar: case 6 can benefit from type switch with assignment
check-package: $GOPATH/src/github.com/ethereum/go-ethereum/signer/core/abihelper.go:46:2: typeSwitchVar: case 0 can benefit from type switch with assignment

[GitCop]

Thank you for your contribution! Your commits seem to not adhere to the repository coding standards

• Commit: 85aeb74
• Commits must be prefixed with the package(s) they modify

Please check the contribution guidelines for more details.

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This message was auto-generated by https://gitcop.com

[karalabe]

Really nice, thank you!

[cristaloleg]

Thanks! 😉