pw_rust: Remove excess newline in doc command line

Change-Id: I23bea68d94a10d645b839f58d1560d982b243975
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/182451
Commit-Queue: Auto-Submit <auto-submit@pigweed-service-accounts.iam.gserviceaccount.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Armando Montanez <amontanez@google.com>
Pigweed-Auto-Submit: Anthony DiGirolamo <tonymd@google.com>
diff --git a/pw_rust/docs.rst b/pw_rust/docs.rst
index d2d0a3c..02e377c 100644
--- a/pw_rust/docs.rst
+++ b/pw_rust/docs.rst
@@ -22,7 +22,7 @@
 .. code-block:: bash
 
    $ bazel build //pw_rust/examples/embedded_hello:hello \
-     --platforms //pw_build/platforms:${PLATFORM} \
+     --platforms //pw_build/platforms:${PLATFORM}
 
    $ qemu-system-arm \
      -machine ${PLATFORM} \