Linux x86 low-level debug register comment synchronization

Linux x86 low-level debug register comment synchronization

This commit updates comments in the low-level debug register code for
Linux x86, making GDB's and gdbserver's implementations identical.

gdb/ChangeLog:

	* x86-linux-nat.c (x86_linux_dr_get): Update comments.
	(x86_linux_dr_set): Likewise.
	(x86_linux_dr_get_addr): Likewise.
	(x86_linux_dr_get_control): Likewise.
	(x86_linux_dr_get_status): Likewise.
	(update_debug_registers_callback): Likewise.
	(x86_linux_dr_set_control): Likewise.
	(x86_linux_dr_set_addr): Likewise.
	(x86_linux_prepare_to_resume): Likewise.
	(x86_linux_new_thread): Likewise.

gdb/gdbserver/ChangeLog:

	* linux-x86-low.c (x86_linux_dr_get): Update comments.
	(x86_linux_dr_set): Likewise.
	(update_debug_registers_callback): Likewise.
	(x86_linux_dr_set_addr): Likewise.
	(x86_linux_dr_get_addr): Likewise.
	(x86_linux_dr_set_control): Likewise.
	(x86_linux_dr_get_control): Likewise.
	(x86_linux_dr_get_status): Likewise.
	(x86_linux_prepare_to_resume): Likewise.