pp_hot.c: pp_rv2av: Squash repetitive code

pp_hot.c: pp_rv2av: Squash repetitive code

The LVRET that I removed (in the if(SvTYPE(sv) == type) block) actu-
ally never evaluates to true, because that block is only entered for
%hash->{elem} or @array->[elem], in which the parent op is helem or
aelem, not leavesublv or return.  LVRET only returns true if the cur-
rent op is the last op in an lvalue sub.  Likewise, the OPpMAYBE_LVSUB
flag is never set in that case, so checking it now is harmless (the
cases that used to enter the if(SvTyPE(sv)==type) block now fall
through to the OPpMAYBE_LVSUB check).

(Using LVRET in pp_rv2av is actually incorrect, and I corrected most instances in 40c94d11, but this one remained.)