[VK] Fix asserts with incorrect memory allocations (#357)

This fixes many assertions with incorrect memory allocations. Regression introduced in PR 334.

Co-authored-by: JPikachu <jpikachu.eden@gmail.com>
Co-authored-by: MaranBr <maranbr@outlook.com>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/357
Reviewed-by: Lizzie <lizzie@eden-emu.dev>
Reviewed-by: crueter <crueter@eden-emu.dev>
Co-authored-by: JPikachu <jpikachu@eden-emu.dev>
Co-committed-by: JPikachu <jpikachu@eden-emu.dev>

src/video_core/vulkan_common/vulkan_device.cpp

@@ -1378,13 +1378,13 @@ void Device::CollectPhysicalMemoryInfo() {
         device_access_memory += mem_properties.memoryHeaps[element].size;
     }
     if (!is_integrated) {
-        const u64 reserve_memory = std::min<u64>(device_access_memory / 4, 2_GiB);
+        const u64 reserve_memory = std::min<u64>(device_access_memory / 8, 1_GiB);
         device_access_memory -= reserve_memory;
 
         if (Settings::values.vram_usage_mode.GetValue() != Settings::VramUsageMode::Aggressive) {
             // Account for resolution scaling in memory limits
-            const size_t normal_memory = 8_GiB;
-            const size_t scaler_memory = 2_GiB * Settings::values.resolution_info.ScaleUp(1);
+            const size_t normal_memory = 6_GiB;
+            const size_t scaler_memory = 1_GiB * Settings::values.resolution_info.ScaleUp(1);
             device_access_memory =
                 std::min<u64>(device_access_memory, normal_memory + scaler_memory);
         }
@@ -1393,7 +1393,7 @@ void Device::CollectPhysicalMemoryInfo() {
     }
     const s64 available_memory = static_cast<s64>(device_access_memory - device_initial_usage);
     device_access_memory = static_cast<u64>(std::max<s64>(
-        std::min<s64>(available_memory - 4_GiB, 6_GiB), std::min<s64>(local_memory, 6_GiB)));
+        std::min<s64>(available_memory - 8_GiB, 6_GiB), std::min<s64>(local_memory, 6_GiB)));
 }
 
 void Device::CollectToolingInfo() {