Tweak ARM process record

Tweak ARM process record

This patch removes the printing "Process record does not support",
and do the print by calling arm_record_unsupported_insn in the
caller.  Also, call arm_record_extension_space only when condition
is 0xf.

gdb:

2016-03-04  Yao Qi  <yao.qi@linaro.org>

	* arm-tdep.c (arm_record_extension_space): Remove code
	printing "Process record does not support".
	(arm_record_data_proc_misc_ld_str): Likewise.
	(decode_insn): Call arm_record_extension_space if condition
	is 0xf.  Call arm_record_unsupported_insn if ret isn't
	ARM_RECORD_SUCCESS.  Use 'ret' instead of 'insn_id' to hold
	the value of thumb2_record_decode_insn_handler.