[llvm-objcopy] Append '\n' to warning messages

Currently the warning message of `llvm-strip %t.o %t.o` does not include
the trailing newline. Fix this by appending a '\n'.

This is the only warning llvm-objcopy and llvm-strip can issue.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D66475

llvm-svn: 369391
diff --git a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
index e937217..9c0145f 100644
--- a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
+++ b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
@@ -84,7 +84,7 @@
 
 ErrorSuccess reportWarning(Error E) {
   assert(E);
-  WithColor::warning(errs(), ToolName) << toString(std::move(E));
+  WithColor::warning(errs(), ToolName) << toString(std::move(E)) << '\n';
   return Error::success();
 }