<rdar://problem/15192088>

gdb-format a (as in p/a) would fail as it needed to set a byte size (unsurprisingly enough)
This should be acknowledged by the condition check and not cause a failure



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@192511 91177308-0d34-0410-b5e6-96231b3b80d8