Fix more unused variable warnings when asserts are disabled.

llvm-svn: 292598
diff --git a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
index 32e6765..a20b709 100644
--- a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
+++ b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
@@ -1532,6 +1532,7 @@
     assert((proc_entry_info.GetRange().GetRangeBase() >= prev_base_address) &&
            "descending /proc/pid/maps entries detected, unexpected");
     prev_base_address = proc_entry_info.GetRange().GetRangeBase();
+    UNUSED_IF_ASSERT_DISABLED(prev_base_address);
 
     // If the target address comes before this entry, indicate distance to next
     // region.