temporal-sql-tool: add missing err returns

[danielhochman]

What changed?
There were two instances I found in temporal-sql-tool where an error was logged but not returned, causing execution to continue erroneously and ultimately panic.

I think using Fatal instead of Error would be better than having to ensure these returns are everywhere, but I wanted to keep the change set small.

Why?
In my case this resulted in a harmless panic when running the update-schema command of temporal-sql-tool with a bad password.

Before

Error is logged and execution continues.

panic: runtime error: invalid memory address or nil pointer dereference ...

2021-12-02T14:42:21.990-0600 ERROR Unable to connect to SQL database. {"error": "pq: password authentication failed for user "temporal_admin"", "logging-call-at": "handler.go:73"}
2021-12-02T14:42:21.990-0600 INFO UpdateSchemeTask started {"config": {"DBName":"","TargetVersion":"","SchemaDir":"/tmp/temporal-1.13.1/schema/postgresql/v96/temporal/versioned","IsDryRun":false}, "logging-call-at": "updatetask.go:98"}
panic: runtime error: invalid memory address or nil pointer dereference
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x10 pc=0xec4114]

goroutine 1 [running]:
go.temporal.io/server/tools/sql.(*Connection).Close(0xc000050000)
/tmp/temporal-1.13.1/tools/sql/conn.go:123 +0x14
panic({0xf7ea00, 0x1a85d60})
/usr/local/go/src/runtime/panic.go:1038 +0x215
go.temporal.io/server/tools/sql.(*Connection).ReadSchemaVersion(0x12c01c0)
/tmp/temporal-1.13.1/tools/sql/conn.go:68 +0x14
go.temporal.io/server/tools/common/schema.(*UpdateTask).Run(0xc00069f5e8)
/tmp/temporal-1.13.1/tools/common/schema/updatetask.go:107 +0x29b
go.temporal.io/server/tools/common/schema.Update(0x12c01c0, {0x12f44a0, 0x0}, {0x12f0178, 0xc00040de00})
/tmp/temporal-1.13.1/tools/common/schema/handler.go:48 +0x98
go.temporal.io/server/tools/sql.updateSchema(0x7f2c01ad8628, {0x12f0178, 0xc00040de00})
/tmp/temporal-1.13.1/tools/sql/handler.go:77 +0x586
go.temporal.io/server/tools/sql.cliHandler(0x2, 0x112c970, {0x12f0178, 0xc00040de00})
/tmp/temporal-1.13.1/tools/sql/main.go:48 +0x56
go.temporal.io/server/tools/sql.BuildCLIOptions.func2(0xc00017f600)
/tmp/temporal-1.13.1/tools/sql/main.go:185 +0x2b
github.com/urfave/cli.HandleAction({0xf370c0, 0xc00040de20}, 0xd)
/home/dhochman/go/pkg/mod/github.com/urfave/cli@v1.22.5/app.go:526 +0x50
github.com/urfave/cli.Command.Run({{0x10b5fc1, 0xd}, {0x0, 0x0}, {0xc00040de60, 0x1, 0x1}, {0x10e3812, 0x27}, {0x0, ...}, ...}, ...)
/home/dhochman/go/pkg/mod/github.com/urfave/cli@v1.22.5/command.go:173 +0x652
github.com/urfave/cli.(*App).Run(0xc0001728c0, {0xc000032100, 0x10, 0x10})
/home/dhochman/go/pkg/mod/github.com/urfave/cli@v1.22.5/app.go:277 +0x705
go.temporal.io/server/tools/sql.RunTool({0xc000032100, 0x10, 0x10})
/tmp/temporal-1.13.1/tools/sql/main.go:42 +0x3c
main.main()
/tmp/temporal-1.13.1/cmd/tools/sql/main.go:36 +0x2e

After

Error is logged and execution ends.

2021-12-02T14:43:05.462-0600    ERROR   Unable to connect to SQL database.      {"error": "pq: password authentication failed for user \"temporal_admin\"", "logging-call-at": "handler.go:73"}

How did you test it?
Manually

Potential risks
None

Is hotfix candidate?
No

[CLAassistant]

All committers have signed the CLA.

[yiminc]

@danielhochman could you please sign the CLA or we won't be able to merge this PR.

[danielhochman]

@yiminc I'm aware and working on it, waiting on some internal review and approval here.

[yiminc]

@danielhochman, any update on the CLA? We would like to get this merged. If we could not have this merged by 12/31, we would abandon this PR and produce our own fix for this.