[patch/rfc] don't try to load directories when searching for an ELF

[Roland McGrath]

It's working perfectly fine.  A directory is just another file that isn't
an ELF file.

	$ echo 'hi there' > /tmp/lib/libc.so.6
	$ LD_LIBRARY_PATH=/tmp/lib ls
	ls: error while loading shared libraries: /tmp/lib/libc.so.6: file too short