Unify gdb puts functions

Now that filtered and unfiltered output can be treated identically, we
can unify the puts family of functions.  This is done under the name
"gdb_puts".  Most of this patch was written by script.

gdb/linux-tdep.c

@@ -944,7 +944,7 @@ linux_info_proc (struct gdbarch *gdbarch, const char *args,
       gdb::unique_xmalloc_ptr<char> status
 	= target_fileio_read_stralloc (NULL, filename);
       if (status)
-	puts_filtered (status.get ());
+	gdb_puts (status.get ());
       else
 	warning (_("unable to open /proc file '%s'"), filename);
     }