Fix one other instance

cmd/buf/internal/command/mod/internal/internal.go

diff --git a/cmd/buf/internal/command/mod/internal/internal.go b/cmd/buf/internal/command/mod/internal/internal.go
index 2aa5a5a..f3a5d96 100644
--- a/cmd/buf/internal/command/mod/internal/internal.go
+++ b/cmd/buf/internal/command/mod/internal/internal.go
@@ -129,11 +129,13 @@
 		fmt.Sprintf(
 			"List all the rules for the given configuration version. Implies --%s. Must be one of %s",
 			allFlagName,
-			xslices.Map(
-				bufconfig.AllFileVersions,
-				func(fileVersion bufconfig.FileVersion) string {
-					return fileVersion.String()
-				},
+			xstrings.SliceToString(
+				xslices.Map(
+					bufconfig.AllFileVersions,
+					func(fileVersion bufconfig.FileVersion) string {
+						return fileVersion.String()
+					},
+				),
 			),
 		),
 	)