Provide page-aligned length to ftruncate.
Provide page-aligned length to ftruncate.

For some files such as hugepages files, ftruncate() fails with the error
"Invalid argument" if the 'length' parameter is not on a page boundary.

Change-Id: I42a9cde98707da15e3c5d1653046e2277fc7a424
Signed-off-by: Igor Mikhailov (imichail) <8c2fe6d2776b9e4026f520f6a4a811d1776c3147@cisco.com>

chrisy/vpp,vpp-dev/vpp,chrisy/vpp,vpp-dev/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,vpp-dev/vpp,vpp-dev/vpp,chrisy/vpp,vpp-dev/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,vpp-dev/vpp,vpp-dev/vpp