fix(nvdrv): prevent infinite loop when SMMU address space is exhausted

Fix crash in PinHandle when SMMU allocation fails and unmap queue is empty.
Previously, the code would log an error and continue looping indefinitely,
causing log spam and eventual crash. Now it returns 0 to fail gracefully.

Also fix incorrect handle check on line 219 - should check freeHandleDesc
instead of handle_description.

Signed-off-by: Zephyron <zephyron@citron-emu.org>

src/core/hle/service/nvdrv/core/nvmap.cpp

@@ -1,5 +1,6 @@
 // SPDX-FileCopyrightText: 2022 yuzu Emulator Project
 // SPDX-FileCopyrightText: 2022 Skyline Team and Contributors
+// SPDX-FileCopyrightText: 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 #include <functional>
@@ -216,10 +217,12 @@ DAddr NvMap::PinHandle(NvMap::Handle::Id handle, bool low_area_pin) {
                     // Handles in the unmap queue are guaranteed not to be pinned so don't bother
                     // checking if they are before unmapping
                     std::scoped_lock freeLock(freeHandleDesc->mutex);
-                    if (handle_description->d_address)
+                    if (freeHandleDesc->d_address)
                         UnmapHandle(*freeHandleDesc);
                 } else {
                     LOG_CRITICAL(Service_NVDRV, "Ran out of SMMU address space!");
+                    // Break out of the loop to prevent infinite spinning when no handles can be freed
+                    return 0;
                 }
             }