Fix misspellings in keystone

Fix misspellings detected by:
* pip install misspellings
* git ls-files | grep -v locale | misspellings -f -

Change-Id: I6c6a2d8f2873f2af81c2dd761da9f71021cee9c4
Closes-Bug: #1257295
Merge "Fix misspellings in keystone"