fix(agc): report a failed PROCMAP_QUERY instead of rescanning the maps

Co-Authored-By: Claude <noreply@anthropic.com>

core/libs/prx/libSceAgcDriver/Execution/src/GuestMemory.cpp

@@ -609,6 +609,7 @@ bool describePages(std::uintptr_t address, std::size_t bytes, Emit&& emit) {
                 static_cast<void>(emit(PageRun{cursor, end, false, false}));
                 return true;
             }
+            return false;
         }
         std::ifstream maps("/proc/self/maps");
         if (!maps.is_open()) return false;