tool_binmode.c: Explicitly ignore the return code of setmode

Fixes code analysis warning C6031:
return value ignored: <function> could return unexpected value
tool_urlglob.c: Silence warning C6293: Ill-defined for-loop

The >= 0 is actually not required, since i underflows and
the for-loop is stopped using the < condition, but this
makes the VS2012 compiler and code analysis happy.
tool_urlglob.c: Added braces to clarify the conditions