Fix a FIXME in a testcase about packed structs and calls I left around
while fixing a related bug.  The fix here was simpler than I thought it
would be.

Fixes <rdar://problem/10530444>.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183718 91177308-0d34-0410-b5e6-96231b3b80d8