udevd: fix termination of rule execution

udevd: fix termination of rule execution

LAST_RULE was broken, and I broke TK_END by making it do the same.
It used a "break" which exited the switch statement, but not the loop!

==2953== Invalid read of size 4
==2953==    at 0x4081EE: dump_token (udev-rules.c:859)
==2953==    by 0x40BADB: udev_rules_apply_to_event (udev-rules.c:1849)
==2953==    by 0x403F17: udev_event_execute_rules (udev-event.c:554)
==2953==    by 0x418626: main (test-udev.c:100)
==2953==  Address 0x55ab1f8 is 0 bytes after a block of size 80 alloc'd
==2953==    at 0x4C23082: realloc (vg_replace_malloc.c:429)
==2953==    by 0x40B13B: udev_rules_new (udev-rules.c:1670)
==2953==    by 0x418536: main (test-udev.c:84)
...

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>