all: fix two minor printf bugs spotted by staticcheck

In cmd/cue/cmd we were using a detailed error string as a format string,
which could cause trouble if the detailed error string were to contain
any special characters.

NewAttr had a similar issue; the only current call site leaves str
empty anyway, so there shouldn't be any change in behavior whatsoever.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: I588311a0a3cdacf5df8cc88779aaf6cd4887cb8b
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1168433
Reviewed-by: Roger Peppe <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>

Author: mvdan

cmd/cue/cmd/cmd.go

@@ -165,7 +165,7 @@ Run "cue help commands" for more details on tasks and commands.
 					cmdline += " cmd"
 				}
 				cwd, _ := os.Getwd()
-				fmt.Fprintf(w, errors.Details(err, &errors.Config{Cwd: cwd}))
+				fmt.Fprint(w, errors.Details(err, &errors.Config{Cwd: cwd}))
 				fmt.Fprintln(w, `Ensure custom commands are defined in a "_tool.cue" file.`)
 				fmt.Fprintln(w, "Run 'cue help cmd' to list available custom commands.")
 				if isRootCmd {

internal/internal.go

@@ -264,9 +264,8 @@ func NewAttr(name, str string) *ast.Attribute {
 	buf.WriteByte('@')
 	buf.WriteString(name)
 	buf.WriteByte('(')
-	fmt.Fprintf(buf, str)
+	buf.WriteString(str)
 	buf.WriteByte(')')
-
 	return &ast.Attribute{Text: buf.String()}
 }