Merge printing code

Merge printing code

This commit synchronizes the debug printing code in i386-nat.c and
i386-low.c.

gdb/
2014-06-18  Gary Benson  <gbenson@redhat.com>

	* i386-nat.c (debug_printf): New macro.
	(i386_get_debug_register_length): Likewise.
	(TARGET_HAS_DR_LEN_8): Use above macro.
	(i386_show_dr): Use debug_printf instead of puts_unfiltered
	and printf_unfiltered.  Use phex to format values.

gdb/gdbserver/
2014-06-18  Gary Benson  <gbenson@redhat.com>

	* i386-low.c (i386_get_debug_register_length): New macro.
	(TARGET_HAS_DR_LEN_8): Remove conditional.  Use above macro.
	(i386_show_dr): Use debug_printf instead of fprintf.  Use
	phex to format values.