Add the SBWatchpoint::GetError back, we have clients who use it.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@158092 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/API/SBWatchpoint.cpp b/source/API/SBWatchpoint.cpp
index 76ce57c..594584c 100644
--- a/source/API/SBWatchpoint.cpp
+++ b/source/API/SBWatchpoint.cpp
@@ -90,6 +90,18 @@
     return m_opaque_sp;
 }
 
+SBError
+SBWatchpoint::GetError ()
+{
+    SBError sb_error;
+    lldb::WatchpointSP watchpoint_sp(GetSP());
+    if (watchpoint_sp)
+    {
+        sb_error.SetError(watchpoint_sp->GetError());
+    }
+    return sb_error;
+}
+
 int32_t
 SBWatchpoint::GetHardwareIndex ()
 {