fortify: Ignore intermediate *.tmp files

The test_fortify.sh script generates logs of build-time warnings
for string and memory functions. To ensure the final log file is
updated atomically, the script first writes its output to a temporary
file with a .log.tmp extension. Upon successful completion, this
temporary file is renamed to the final .log file.

If the build process is interrupted before this rename operation,
these *.log.tmp intermediate files will be left in the directory,
creating a risk of them being accidentally added to the git repository.

To prevent this from happening, add *.tmp to the .gitignore file to
explicitly ignore these temporary files.

Signed-off-by: WangYuli <wangyl5933@chinaunicom.cn>
Signed-off-by: WangYuli <wangyuli@aosc.io>

Author: Avenger-285714

lib/test_fortify/.gitignore

@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
 /*.log
+/*.tmp