Removed explicit NULL checks for shared pointers
and instead made us use implicit casts to bool.
This generated a warning in C++11.

<rdar://problem/11930775>

llvm-svn: 161559
diff --git a/lldb/source/Expression/ClangUserExpression.cpp b/lldb/source/Expression/ClangUserExpression.cpp
index 029b153..b1bef73 100644
--- a/lldb/source/Expression/ClangUserExpression.cpp
+++ b/lldb/source/Expression/ClangUserExpression.cpp
@@ -572,7 +572,7 @@
                                                                           ((m_needs_object_ptr && m_objectivec) ? &cmd_ptr : NULL),
                                                                           shared_ptr_to_me));
         
-        if (call_plan_sp == NULL || !call_plan_sp->ValidatePlan (NULL))
+        if (!call_plan_sp || !call_plan_sp->ValidatePlan (NULL))
             return eExecutionSetupError;
         
         lldb::addr_t function_stack_pointer = static_cast<ThreadPlanCallFunction *>(call_plan_sp.get())->GetFunctionStackPointer();