vi: restore capability to remember insertion cmds for "."

vi: restore capability to remember insertion cmds for "."

function                                             old     new   delta
modifying_cmds                                        17      22      +5
get_one_char                                         103      98      -5
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 5/-5)                Total: 0 bytes
   text	   data	    bss	    dec	    hex	filename
 982121	    485	   7296	 989902	  f1ace	busybox_old
 982094	    485	   7296	 989875	  f1ab3	busybox_unstripped

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