process-util: don't use overly large buffer to store process command line
    
    Allocate new string as a return value and free our "scratch pad"
    buffer that is potentially much larger than needed (up to
    _SC_ARG_MAX).
    
    Fixes #11502
    
    (cherry-picked from commit eb1ec489eef8a32918bbfc56a268c9d10464584d)
    
    Related: #1664976
    
    patch_name: 0077-process-util-don-t-use-overly-large-buffer-to-store-.patch
    present_in_specfile: true
    location_in_specfile: 77
    squash_commits: true