rx_check_imei_req(): fix IMEI bounds checking

IMEIs (without the checksum) always have 14 digits. Replace the previous
check (length <= 14) with a proper one (length == 14) and set the buffer
to the right size. While at it, add the return code of
gsm48_decode_bc_number2() to the error log message.

I have tested with new TTCN3 tests, that the length check is working
properly now.

Related: OS#2541
Change-Id: I060a8db98fb882e4815d1709a5d85bc0143a73a6
1 file changed