[LLDB] Remove dead code (NFC) (#95713)

The dead code is caught by PVS studio analyzer -
https://pvs-studio.com/en/blog/posts/cpp/1126/, fragment N12.

Warning message -
V523 The 'then' statement is equivalent to the 'else' statement.
Options.cpp 1212

Author: xgupta

lldb/source/Interpreter/Options.cpp

@@ -1197,21 +1197,12 @@ OptionElementVector Options::ParseForCompletion(const Args &args,
         }
         break;
       case OptionParser::eOptionalArgument:
-        if (OptionParser::GetOptionArgument() != nullptr) {
-          option_element_vector.push_back(OptionArgElement(
-              opt_defs_index,
-              FindOriginalIndex(dummy_vec[OptionParser::GetOptionIndex() - 2],
-                                args),
-              FindOriginalIndex(dummy_vec[OptionParser::GetOptionIndex() - 1],
-                                args)));
-        } else {
-          option_element_vector.push_back(OptionArgElement(
-              opt_defs_index,
-              FindOriginalIndex(dummy_vec[OptionParser::GetOptionIndex() - 2],
-                                args),
-              FindOriginalIndex(dummy_vec[OptionParser::GetOptionIndex() - 1],
-                                args)));
-        }
+        option_element_vector.push_back(OptionArgElement(
+            opt_defs_index,
+            FindOriginalIndex(dummy_vec[OptionParser::GetOptionIndex() - 2],
+                              args),
+            FindOriginalIndex(dummy_vec[OptionParser::GetOptionIndex() - 1],
+                              args)));
         break;
       default:
         // The options table is messed up.  Here we'll just continue