find: remove the hack we use to parse options first, replace with simpler code

find: remove the hack we use to parse options first, replace with simpler code

   text	   data	    bss	    dec	    hex	filename
 867764	    438	   7552	 875754	  d5cea	busybox_old
 867629	    438	   7552	 875619	  d5c63	busybox_unstripped

function                                             old     new   delta
parse_params                                        1377    1440     +63
static.params                                        151     192     +41
static.options                                        42      57     +15
fileAction                                           151     153      +2
find_main                                            466     267    -199
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/1 up/down: 121/-199)          Total: -78 bytes

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