modprobe-small: move lsmod code out of modprobe_main()

modprobe-small: move lsmod code out of modprobe_main()

Having lsmod code inside modprobe_main() makes some of the applet name
checking code awkward. Besides, this make busybox x86_64 binary a few
bytes smaller. :)

function                                  old     new   delta
lsmod_main                                  -      23     +23
modprobe_main                             599     564     -35
-------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/1 up/down: 23/-35) Total: -12 bytes

Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>