memory: take the address-space lock shared for tracker protections

src/kernel/memoryAddressSpace.inc

@@ -820,12 +820,12 @@ public:
 		return ProtectMappedUnlocked(vaddr, size, mode);
 	}
 
+	// Tracker protections only read m_mapped; the page tracker orders them per page.
 	bool ProtectTransient(uint64_t vaddr, uint64_t size, VirtualMemory::Mode mode) {
 		if (size == 0 || UINT64_MAX - vaddr < size) {
 			return false;
 		}
-
-		std::lock_guard lock(m_mutex);
+		std::shared_lock lock(m_mutex);
 		return ProtectMappedUnlocked(vaddr, size, mode);
 	}