ash: speed up NOFORK code in ash by eliminating second find_applet().

ash: speed up NOFORK code in ash by eliminating second find_applet().
some code reduction along the way.

function                                             old     new   delta
run_list                                            1971    1981     +10
run_nofork_applet_prime                              181     182      +1
unsetcmd                                              97      96      -1
delete_cmd_entry                                      54      53      -1
describe_command                                     399     397      -2
cmdlookup                                            152     150      -2
evaltreenr                                           602     599      -3
evaltree                                             602     599      -3
clearcmdentry                                        101      98      -3
cdcmd                                                675     672      -3
hashcmd                                              305     301      -4
find_command                                         933     910     -23
evalcommand                                         1371    1229    -142
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/11 up/down: 11/-187)         Total: -176 bytes