* remote.c (remote_write_bytes): Take a const buffer argument.

	* remote.c (remote_write_bytes): Take a const buffer argument.
	Do the checks from remote_xfer_memory.
	(remote_read_bytes): Do the checks from remote_xfer_memory.
	(remote_xfer_memory): Remove checks pushed into lower level
	functions.
	(remote_xfer_partial): Call remote_write_bytes and remote_read_bytes
	directly.
	* remote.h (remote_write_bytes): Update prototype.