gdb: remove file_handler typedef

Remove the typedef (unneeded with C++).  Re-format the comments to
follow the more common style.

gdbsupport/ChangeLog:

	* event-loop.c (struct file_handler): Remove typedef, re-format.

Change-Id: I3aea21fba1eb2584c507de3412da4e4c98283b2d
2 files changed