UI/updater: Fix files with similar hashes clashing

Do to multithreading the update process, files of the same hash can
sometimes collide due to race. Ensure the filenames are all unique by
appending an incremented value for each file.

UI/win-update/updater/updater.cpp

@@ -885,12 +885,16 @@ static void UpdateWithPatchIfAvailable(const char *name, const char *hash,
 		update.fileSize = size;
 		update.patchable = true;
 
+		/* ensure the filename is unique */
+		static long increment = 0;
+
 		/* Since the patch depends on the previous version, we can
 		 * no longer rely on the temp name being unique to the
 		 * new file's hash */
 		update.tempPath = tempPath;
 		update.tempPath += L"\\";
 		update.tempPath += patchHashStr;
+		update.tempPath += std::to_wstring(increment++);
 		break;
 	}
 }