[IA64] ia64 does not need umount2() syscall
[IA64] ia64 does not need umount2() syscall

ia64 doesn't have old and new versions of the umount system call.
It just has the new version.

Fixes this build warning:
<stdin>:395:2: warning: #warning syscall umount2 not implemented

Signed-off-by: Tony Luck <e7984595ec0368ff920a7b3521dc7093683f6f26@intel.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs