changes to compile on linux with gcc v12 + Dockerfile

[CristiMacovei]

Made changes to compile the project on linux targets using gcc version 12.2.

• a variable named debug was defined in two places in dfu-util/

  • changed dfu-util/dfu.h: removed declaration of debug variable
  • changed dfu-util/sam7dfu.c: added extern declaration of debug
  • kept definition in dfu-util/main.c

• a variable named endianness was already defined and redefined inside ipsw-patch/main.c and xpwn/src/xpwn.cpp

  • added extern modifier to the declaration

[razvand]

Please improve the commit messages. Use instructions here.

Also, I would add / update the README file with instructions on using the Dockerfile.

[razvand]

Suggested change

	RUN apt update && apt upgrade -y
	RUN apt install -y git cmake build-essential libz-dev libssl-dev libbz2-dev libpng-dev libusb-dev
	RUN set -xe; \
	apt-get -yqq update; \
	apt-get install -y git cmake build-essential libz-dev libssl-dev libbz2-dev libpng-dev libusb-dev \
	;

[razvand]

Update your commit messages to follow the best practices in creating commits and commit descriptions.

That is:

1. Use your full name for signing-off and for commit authorship: Cristian Macovei <nicolae.macovei1412@stud.acs.upb.ro>.
2. Start sentences with capital letters, e.g. use Improve instead of improve.
3. When you add a new file, do not use the verb Add. Use the verb Introduce.
4. Use capitalized words for names, e.g. Git instead of git, GCC instead of GCC.
5. Add a detailed description for commit messages, e.g. the commit add Docker pipeline (the first line should be Introduce Docker pipeline - followed by an extended description). Same for add Dockerfile and changes to compile on linux with gcc v12 (which should be Update code to build on Linux with GCC >= 12.

[razvand]

Suggested change

	xpwn $ docker build -t <container_name> .
	docker build -t <container_name> .

[razvand]

Suggested change

	# Docker usage instructions
	# Docker Usage Instructions

[razvand]

Suggested change

	Container images are available on [the github container registry](https://github.com/orgs/malus-security/packages/container/package/xpwn) (and soon on the gitlab container registry).
	Container images are available on [the GitHub Container Registry](https://github.com/orgs/malus-security/packages/container/package/xpwn) (and soon on the GitLab Container Registry).