Comment and whitespace changes

Comment and whitespace changes

Comments on the various implementations of target fileio functions
duplicate information documented in target.h.  This commit replaces
the duplicated documentation with breadcrumbs, and inserts blank
lines to separate comments from the functions they describe where
necessary.

gdb/ChangeLog:

	* inf-child.c (inf_child_fileio_open): Replace comment.
	(inf_child_fileio_pwrite): Likewise.
	(inf_child_fileio_pread): Likewise.
	(inf_child_fileio_fstat): Insert blank line before comment.
	(inf_child_fileio_close): Replace comment.
	(inf_child_fileio_unlink): Likewise.
	(inf_child_fileio_readlink): Likewise.
	* remote.c (remote_hostio_open): Likewise.
	(remote_hostio_pread): Likewise.
	(remote_hostio_pwrite): Likewise.
	(remote_hostio_close): Likewise.
	(remote_hostio_unlink): Likewise.
	(remote_hostio_readlink): Likewise.
	(remote_hostio_fstat): Likewise.
	(remote_filesystem_is_local): Likewise.
	* target.c (target_fileio_open): Likewise.
	(target_fileio_pwrite): Likewise.
	(target_fileio_pread): Likewise.
	(target_fileio_fstat): Insert blank line before comment.
	(target_fileio_close): Replace comment.
	(target_fileio_unlink): Likewise.
	(target_fileio_readlink): Likewise.
	(target_fileio_read_alloc): Likewise.
	(target_fileio_read_stralloc): Likewise.