Fix bazel makefile on Windows

The `make -C bazel generate` command doesn't function properly on
Windows builders because Windows uses backslashes as the path separator.

Fortunately, adding quotes around the path is enough to concince
Windows to run the executable, allowing the `generate` target to
complete successfully, and doing so doesn't impact Linux builders.

Bug: skia:13366
Change-Id: I50c461635b70cc59cd6e79bf17a6945c80df1986
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/544756
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
diff --git a/bazel/Makefile b/bazel/Makefile
index d9cbd01..491c83b 100644
--- a/bazel/Makefile
+++ b/bazel/Makefile
@@ -1,7 +1,7 @@
 # This target should be run when new files are added or includes changed.
 generate:
 	bazelisk build @org_skia_go_infra//bazel/gazelle:gazelle_cpp
-	cd .. && bazel-bin/external/org_skia_go_infra/bazel/gazelle/gazelle_cpp_/gazelle_cpp update \
+	cd .. && "bazel-bin/external/org_skia_go_infra/bazel/gazelle/gazelle_cpp_/gazelle_cpp" update \
 		--third_party_file_map="third_party/file_map_for_bazel.json" \
 		include src tools gm tests \
 		modules/skshaper modules/svg modules/skresources modules/skparagraph modules/skunicode \