sys/syscall.h exist at all os'es instead of <syscall.h> which exist only
at linux.
b=14929
i=nikita

libsysio: fix getdirentries for native fs

b=12949

Clean up libsysio compiler warnings on XT3.

b=12332
i=adilger
i=walter

Update libsysio to latest version.

b=12331

DESCRIPTION:
    keep CFS up to date with latest libsysio version

* the b1_5_* and b_iam* branches will to continue to use the old libsysio
* until they can be updated from b1_4 liblustre because of the API change.

- API changegetdirentries->filldirentries changed from upstream
- symlink following fixup
- fix getcwd for out-of-libsysio directory
- lseek fixups for large files
- flock/fcntl fixups for 64-bit systems