Target: silence a GCC warning

GCC emits a warning:
    warning: enumeral and non-enumeral type in conditional expression [enabled by default]
which does not seem to have a flag to control it.  Simply add an explicit cast
for the boolean value.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@213715 91177308-0d34-0410-b5e6-96231b3b80d8
Plugins: silence a few more signed comparision warnings

Address a few signed-compare warnings that were triggered on GCC 4.8.2.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@213716 91177308-0d34-0410-b5e6-96231b3b80d8