remove double empty lines from end of files.
this was done using the following python script:

import os
for dirpath, dirnames, filenames in os.walk(os.getcwd()):
    if '.' in dirpath:
        continue
    for filename in filenames:
        if not any(filename.endswith(suffix) for suffix in [".c", ".h", ".sh", "Makefile", ".mk"]):
            continue
        fullpath = os.path.join(dirpath, filename)
        try:
            data = open(fullpath, "rb").read()
            if data.endswith("\n\n"):
                open(fullpath, "wb").write(data[:-1])
        except:
            pass