Renode example compiler warning

[Ivan Vnučec]

I've cloned repo and tried to build Renode example in /example/renode with make command and the following compiler warning occured:

renode-example.c:53:5: warning: no previous prototype for '_write' [-Wmissing-prototypes]
   53 | int _write(int file, char *ptr, int len)
      |     ^~~~~~

To fix the warning I've added function prototype

int _write(int file, char *ptr, int len);

to the top of the renode-example.c file.

I can add pull req to resolve this issue.

INFO:
Compiler version arm-none-eabi-gcc (15:9-2019-q4-0ubuntu1) 9.2.1 20191025 (release) [ARM/arm-9-branch revision 277599]

[Noah Pendleton]

Thank you for posting this issue! I believe this is closed by #268