Re: [SMS D-Bus 01/19] write_file: make transaction-safe

From: Inaky Perez-Gonzalez <inaky.perez-gonzalez(a)intel.com&gt; write_file(), as written wasn't transaction-safe; a crash bewtween a file being open and the buffer being written before a safe close would leave the file with a set of undetermined contents. Modified to the file is written to a temporary file name; once completed, it is renamed to the final name. This way, a crash in the middle doesn't leave half-baked files.