internal/lsp/command: fix typo in comment

Fix a typo in docs for MarshalArgs in internal/lsp/command.

Change-Id: Ib11a31f27b4ebb03b6eecd996ccf600154cd3cd0
Reviewed-on: https://go-review.googlesource.com/c/tools/+/350551
Reviewed-by: Peter Weinberger <pjw@google.com>
Trust: Peter Weinberger <pjw@google.com>
Trust: Pontus Leitzler <leitzler@gmail.com>

internal/lsp/command/util.go

@@ -25,7 +25,7 @@ func (c Command) ID() string {
 //
 // Example usage:
 //
-//   jsonArgs, err := EncodeArgs(1, "hello", true, StructuredArg{42, 12.6})
+//   jsonArgs, err := MarshalArgs(1, "hello", true, StructuredArg{42, 12.6})
 //
 func MarshalArgs(args ...interface{}) ([]json.RawMessage, error) {
 	var out []json.RawMessage