IGF initialization error

(content shamelessly stolen from sa4/audio/ivas-basop#2060 (closed))

Bug description

Running self-test condition with bitrate/bandwidth switching returns several error messages in the float encoder. The encoder does not crash though.

------ Running the encoder ------

Frames processed:       IGFEncSetMode_fx: initialization error!
IGFEncSetMode_fx: initialization error!
IGFEncSetMode_fx: initialization error!
IGFEncSetMode_fx: initialization error!
1000

Encoding of 1000 frames finished
Press any key to continue . . .

Ways to reproduce

IVAS_cod -max_band scripts/testv/ivas_bws_20fr_start_WB.txt -mc 5_1 scripts/switchPaths/sw_24k4_256k.bin 48 scripts/testv/stv51MC48c.wav bit