ps: fix overflow in USER and VSZ columns

ps: fix overflow in USER and VSZ columns

function                                             old     new   delta
smart_ulltoa4                                          -     280    +280
smart_ulltoa5                                        283     408    +125
ulltoa6_and_space                                      -      25     +25
scale                                                 28      38     +10
bbunpack                                             358     366      +8
ps_main                                              259     261      +2
glob3                                                 35      37      +2
fill_bounds                                          172     174      +2
process_stdin                                        456     446     -10
smart_ulltoa6                                        406       -    -406
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(add/remove: 2/1 grow/shrink: 6/1 up/down: 454/-416)           Total: 38 bytes