CLEANUP/MINOR: doc: fix volume mount path in usage comment

Update the directory path in the Docker run command within the block_secrets_test.sh usage instructions. The path was changed from $PWD/pkg/protection to $PWD/hug/protection to align with the current repository structure.

Author: oktalz

hug/protection/block_secrets_test.sh

@@ -7,7 +7,7 @@
 # Builds libblock_secrets.so and runs block_secrets_test.c under LD_PRELOAD.
 # Designed to run inside the musl/alpine build image so the test exercises the
 # same libc as production. Usage:
-#   docker run --rm -v "$PWD/pkg/protection":/p:ro haproxytech/haproxy-alpine:3.2 \
+#   docker run --rm -v "$PWD/hug/protection":/p:ro haproxytech/haproxy-alpine:3.2 \
 #       sh -c 'apk add --no-cache build-base >/dev/null && cp /p/* /tmp && /tmp/block_secrets_test.sh'
 set -eu