pw_system: Reword log stream error message
pw_system: Reword log stream error message

Change-Id: If52b5b362c5773ac591a14dc96bcd5450e6a7907
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/74940
Pigweed-Auto-Submit: Carlos Chinchilla <cdf38d65522bb1d68fb5b958430f926735c310be@google.com>
Reviewed-by: Armando Montanez <97ef6fdb231c129ac8827d9f0c4106bfbf57f74f@google.com>
Commit-Queue: Auto-Submit <14637eda5603879df170705285bf30f5996692f0@pigweed.google.com.iam.gserviceaccount.com>

google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed