memcpy() in wmi_set_ie() and wmi_update_ft_ies() is called with
src == NULL and len == 0. This is an undefined behavior. Fix it
by checking "ie_len > 0" before the memcpy() calls.
As suggested by GCC documentation:
"The pointers passed to memmove (and similar functions in <string.h>)
must be non-null even when nbytes==0, so GCC can use that information
to remove the check after the memmove call." [1]