[Bazel] fix typo

Author: Dmitry Chernenkov

utils/bazel/llvm-project-overlay/mlir/test/Dialect/BUILD.bazel

@@ -35,7 +35,7 @@ package(default_visibility = ["//visibility:public"])
             "Transform/*-symbol-decl-and-schedule.mlir",
             "Transform/*-symbol-decl-dir.mlir",
             "Transform/*-symbol-decl-invalid.mlir",
-            "Transform/Library/*.mlir"
+            "Transform/Library/*.mlir",
             "Transform/preload-library.mlir",
             "Transform/test-interpreter-library/*.mlir",
             "Transform/test-repro-dump.mlir",