procfs-util: expose functionality to query total memory
    
    procfs_memory_get_current is renamed to procfs_memory_get_used, because
    "current" can mean anything, including total memory, used memory, and free
    memory, as long as the value is up to date.
    
    No functional change.
    
    (cherry-picked from commit c482724aa5c5d0b1391fcf958a9a3ea6ce73a085)
    
    Related: #1664976
    
    patch_name: 0073-procfs-util-expose-functionality-to-query-total-memo.patch
    present_in_specfile: true
    location_in_specfile: 73
    squash_commits: true