Fix configure_bazel.py on Linux.

Closes https://github.com/google/iree/pull/2085

COPYBARA_INTEGRATE_REVIEW=https://github.com/google/iree/pull/2085 from ScottTodd:bazel-linux-fix db2661324e0741d688d207f352f84602bda87058
PiperOrigin-RevId: 314344811
diff --git a/configure_bazel.py b/configure_bazel.py
index 34d0f6a..099dd2c 100644
--- a/configure_bazel.py
+++ b/configure_bazel.py
@@ -22,6 +22,7 @@
   if platform.system() == "Windows":
     # Sure. Good idea, bazel.
     return p.replace("\\", "/")
+  return p
 
 
 def write_platform(bazelrc):