Replace 'ap' with 'up' suffix in variable names. (NFC)

The `ap` suffix is a remnant of lldb's former use of auto pointers,
before they got deprecated. Although all their uses were replaced by
unique pointers, some variables still carried the suffix.

In r353795 I removed another auto_ptr remnant, namely redundant calls to
::get for unique_pointers. Jim justly noted that this is a good
opportunity to clean up the variable names as well.

I went over all the changes to ensure my find-and-replace didn't have
any undesired side-effects. I hope I didn't miss any, but if you end up
at this commit doing a git blame on a weirdly named variable, please
know that the change was unintentional.

llvm-svn: 353912
diff --git a/lldb/source/Interpreter/Options.cpp b/lldb/source/Interpreter/Options.cpp
index bd29d5d..87e09e5 100644
--- a/lldb/source/Interpreter/Options.cpp
+++ b/lldb/source/Interpreter/Options.cpp
@@ -760,7 +760,7 @@
     CompletionRequest &request, OptionElementVector &opt_element_vector,
     int opt_element_index, CommandInterpreter &interpreter) {
   auto opt_defs = GetDefinitions();
-  std::unique_ptr<SearchFilter> filter_ap;
+  std::unique_ptr<SearchFilter> filter_up;
 
   int opt_arg_pos = opt_element_vector[opt_element_index].opt_arg_pos;
   int opt_defs_index = opt_element_vector[opt_element_index].opt_defs_index;
@@ -831,7 +831,7 @@
               interpreter.GetDebugger().GetSelectedTarget();
           // Search filters require a target...
           if (target_sp)
-            filter_ap.reset(new SearchFilterByModule(target_sp, module_spec));
+            filter_up.reset(new SearchFilterByModule(target_sp, module_spec));
         }
         break;
       }
@@ -839,7 +839,7 @@
   }
 
   return CommandCompletions::InvokeCommonCompletionCallbacks(
-      interpreter, completion_mask, request, filter_ap.get());
+      interpreter, completion_mask, request, filter_up.get());
 }
 
 void OptionGroupOptions::Append(OptionGroup *group) {