ash: 16-bit ->nprocs field is a pain for many CPUs

ash: 16-bit ->nprocs field is a pain for many CPUs

function                                             old     new   delta
getoptscmd                                           527     540     +13
getjob                                               280     286      +6
makejob                                              278     282      +4
forkchild                                            602     600      -2
waitcmd                                              208     205      -3
showjob                                              382     379      -3
getstatus                                             83      80      -3
dowait                                               408     405      -3
freejob                                               93      89      -4
fg_bgcmd                                             290     286      -4
forkshell                                            260     255      -5
killcmd                                              224     218      -6
jobno                                                 17      11      -6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/10 up/down: 23/-39)           Total: -16 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>