* Use proper int64_t printf format qualifier to fix 64-bit sim compile
  on Mac.
* Minor cleanup to ExecuteInstruction() to remove an unncessary
  'processed' variable.

R=jyan@ca.ibm.com,mbrandy@us.ibm.com,michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1889643002

Cr-Commit-Position: refs/heads/master@{#35460}