In fts_build(), if we try to chdir and fail (e.g. due to lack of search

permission), try to continue in FTS_DONTCHDIR mode.  Of course this
won't work for long paths, but we can't descend more than one pathname
component beyond the directory anyway if we lack search permission.

Here is a transcript demonstrating the change, where oldls is ls(1)
linked with the old fts(3):

	das@VARK:~> mkdir t && touch t/{a,b,c} && chmod u-x t
	das@VARK:~> oldls t
	a       b       c
	das@VARK:~> oldls -l t
	das@VARK:~> \ls t
	a       b       c
	das@VARK:~> \ls -l t
	ls: a: Permission denied
	ls: b: Permission denied
	ls: c: Permission denied

I had forgotten about this patch until bde reminded me.  He reports
using it without problems for over a year.

PR:	45723

lib/libc/gen/fts-compat.c

@@ -710,8 +710,6 @@ fts_build(sp, type)
 			cur->fts_flags |= FTS_DONTCHDIR;
 			descend = 0;
 			cderrno = errno;
-			(void)closedir(dirp);
-			dirp = NULL;
 		} else
 			descend = 1;
 	} else

lib/libc/gen/fts.c

@@ -710,8 +710,6 @@ fts_build(sp, type)
 			cur->fts_flags |= FTS_DONTCHDIR;
 			descend = 0;
 			cderrno = errno;
-			(void)closedir(dirp);
-			dirp = NULL;
 		} else
 			descend = 1;
 	} else