Remove fully inactivated linters (#2148)

* Remove fully inactivated linters

Currently golangci-lint fails with these errors:

ERRO [linters_context] golint: This linter is fully inactivated: it will not produce any reports.
ERRO [linters_context] interfacer: This linter is fully inactivated: it will not produce any reports.
ERRO [linters_context] maligned: This linter is fully inactivated: it will not produce any reports.

I could not find any docs explaining what "fully inactivated" mean, but
based this PR[1] it seems that these linters do nothing now. Removing
the linters fixes this issue without changing linting, as they did not
produce any report.

Looking in the linters docs[2] I did not find a replacement for
"interfacer" and "malinged" linters. "stylecheck" seems to be a
replacement for "golint", but we need to fix the code to enable it.

[1] golangci/golangci-lint#4436
[2] https://golangci-lint.run/usage/linters/

* Add stylecheck linter, replacement for golint

This revealed 2 capitalized error messages.

https://golangci-lint.run/usage/linters/#stylecheck

.golangci.yml

@@ -33,16 +33,13 @@ linters:
     #- gocyclo
     #- gofmt
     - goimports
-    - golint
     #- gomnd
     #- goprintffuncname
     #- gosec
     - gosimple
     - govet
     - ineffassign
-    - interfacer
     #- lll
-    - maligned
     - megacheck
     #- misspell
     #- nakedret
@@ -52,7 +49,7 @@ linters:
     #- scopelint
     #- staticcheck
     #- structcheck ! deprecated since v1.49.0; replaced by 'unused'
-    #- stylecheck
+    - stylecheck
     #- typecheck
     - unconvert
     #- unparam

command.go

@@ -875,7 +875,7 @@ func (c *Command) ArgsLenAtDash() int {
 
 func (c *Command) execute(a []string) (err error) {
 	if c == nil {
-		return fmt.Errorf("Called Execute() on a nil Command")
+		return fmt.Errorf("called Execute() on a nil Command")
 	}
 
 	if len(c.Deprecated) > 0 {

completions.go

@@ -298,7 +298,7 @@ func (c *Command) getCompletions(args []string) (*Command, []string, ShellCompDi
 	}
 	if err != nil {
 		// Unable to find the real command. E.g., <program> someInvalidCmd <TAB>
-		return c, []string{}, ShellCompDirectiveDefault, fmt.Errorf("Unable to find a command for arguments: %v", trimmedArgs)
+		return c, []string{}, ShellCompDirectiveDefault, fmt.Errorf("unable to find a command for arguments: %v", trimmedArgs)
 	}
 	finalCmd.ctx = c.ctx