src: avoid unused variable 'error' warning

The variable is only used in DEBUG mode. Define it only in that case.

PR-URL: #52886
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

src/debug_utils.cc

@@ -182,10 +182,13 @@ class Win32SymbolDebuggingContext final : public NativeSymbolDebuggingContext {
       return NameAndDisplacement(pSymbol->Name, dwDisplacement);
     } else {
       // SymFromAddr failed
-      const DWORD error = GetLastError();  // "eat" the error anyway
 #ifdef DEBUG
+      const DWORD error = GetLastError();
       fprintf(stderr, "SymFromAddr returned error : %lu\n", error);
-#endif
+#else
+      // Consume the error anyway
+      USE(GetLastError());
+#endif  // DEBUG
     }
     // End MSDN code
 
@@ -217,10 +220,13 @@ class Win32SymbolDebuggingContext final : public NativeSymbolDebuggingContext {
       sym.line = line.LineNumber;
     } else {
       // SymGetLineFromAddr64 failed
-      const DWORD error = GetLastError();  // "eat" the error anyway
 #ifdef DEBUG
+      const DWORD error = GetLastError();
       fprintf(stderr, "SymGetLineFromAddr64 returned error : %lu\n", error);
-#endif
+#else
+      // Consume the error anyway
+      USE(GetLastError());
+#endif  // DEBUG
     }
     // End MSDN code
 
@@ -240,10 +246,13 @@ class Win32SymbolDebuggingContext final : public NativeSymbolDebuggingContext {
       return szUndName;
     } else {
       // UnDecorateSymbolName failed
-      const DWORD error = GetLastError();  // "eat" the error anyway
 #ifdef DEBUG
+      const DWORD error = GetLastError();
       fprintf(stderr, "UnDecorateSymbolName returned error %lu\n", error);
-#endif
+#else
+      // Consume the error anyway
+      USE(GetLastError());
+#endif  // DEBUG
     }
     return nullptr;
   }