Minor typo corrections

Change-Id: I5962ba6a9b9285095ddacf00307a3094c697461a
Reviewed-on: https://code.wireshark.org/review/3546
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
(cherry picked from commit 9deb7690963ea1132dd896d853acd976dc8a75c2)
Reviewed-on: https://code.wireshark.org/review/3547