[binutils-gdb] Use gdbpy_ref in py-utils.c

[sergiodj+buildbot at sergiodj dot net]

*** TEST RESULTS FOR COMMIT 830a493402da4a055bf2d34ab300a83305391095 ***

Author: Tom Tromey <tom@tromey.com>
Branch: master
Commit: 830a493402da4a055bf2d34ab300a83305391095

Use gdbpy_ref in py-utils.c

This changes more places in py-utils.c to use gdbpy_ref.

2017-01-10  Tom Tromey  <tom@tromey.com>

	* python/py-utils.c (unicode_to_encoded_string)
	(python_string_to_target_string)
	(python_string_to_target_python_string)
	(python_string_to_host_string, gdbpy_obj_to_string)
	(get_addr_from_python): Use gdbpy_ref.