Valgrind warning from vared -c

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

Doesn't happen on vared of an existing param, as far as I can tell.

==1443300== Conditional jump or move depends on uninitialised value(s)
==1443300==    at 0x2612D1: zleread (zle_main.c:1353)
==1443300==    by 0x263333: bin_vared (zle_main.c:1833)
==1443300==    by 0x12AB3C: execbuiltin (builtin.c:506)
==1443300==    by 0x155B3E: execcmd_exec (exec.c:4187)
==1443300==    by 0x14F2C6: execpline2 (exec.c:2003)
==1443300==    by 0x14DE4D: execpline (exec.c:1728)
==1443300==    by 0x14D0B7: execlist (exec.c:1482)
==1443300==    by 0x14C6E5: execode (exec.c:1263)
==1443300==    by 0x17419D: loop (init.c:212)
==1443300==    by 0x178D12: zsh_main (init.c:1810)
==1443300==    by 0x129BCC: main (main.c:93)


   1352
   1353     if (zleline && *zleline)
   1354         redrawhook();
   1355