gdb.ada/complete.exp: Fix FIXME.

2013-05-16  Pedro Alves  <palves@redhat.com>

	* gdb.ada/complete.exp (test_gdb_no_completion): Fix typo in
	comment.  Use gdb_test_no_output.
	* linux-low.c: Move definition checks upwards for PT_TEXT_ADDR,
	PT_DATA_ADDR and PT_TEXT_END_ADDR.  Update comments.
	(linux_read_offsets): Remove PT_TEXT_ADDR, PT_DATA_ADDR and
	PT_TEXT_END_ADDR guards.  Update comments.
	(linux_target_op) <read_offsets>: Conditionally define to
	linux_read_offsets if the target is UCLIBC and if it defines
	PT_TEXT_ADDR, PT_DATA_ADDR and PT_TEXT_END_ADDR.