pw_env_setup: Ensure PATH is exported

Bug: 281
Change-Id: Ib26cf37f14d6fe51bdc8b0c3dd20dbbd4165f8ce
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/24160
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Reviewed-by: David Rogers <davidrogers@google.com>
diff --git a/pw_env_setup/util.sh b/pw_env_setup/util.sh
index 079b8db..2a1168f 100644
--- a/pw_env_setup/util.sh
+++ b/pw_env_setup/util.sh
@@ -16,6 +16,8 @@
   python -c "import os.path; print(os.path.abspath('$@'))"
 }
 
+# Just in case PATH isn't already exported.
+export PATH
 
 # Note: Colors are unfortunately duplicated in several places; and removing the
 # duplication is not easy. Their locations are: