hlr_ussd.c: avoid using CR and NL in IUSE responses

According to GSM TS 03.38, section 6.1.2.1, CR symbol at the end
is optional, and moreover libosmogsm encoding API will carry
about the bit padding itself.

Change-Id: I09e8a67758698f3b7a578eab956311e269d091ee
1 file changed