sanitise sign comparisons

This is a mechanical change addressing the various sign comparison warnings that
are identified by both clang and gcc.  This helps cleanup some of the warning
spew that occurs during builds.

llvm-svn: 205390
diff --git a/lldb/source/Interpreter/Options.cpp b/lldb/source/Interpreter/Options.cpp
index c6c66d8..ce98757 100644
--- a/lldb/source/Interpreter/Options.cpp
+++ b/lldb/source/Interpreter/Options.cpp
@@ -344,7 +344,7 @@
 
     // Will it all fit on one line?
 
-    if ((len + strm.GetIndentLevel()) < output_max_columns)
+    if (static_cast<uint32_t>(len + strm.GetIndentLevel()) < output_max_columns)
     {
         // Output it as a single line.
         strm.Indent (text);