avcodec/ra144enc: Fix invalid left shift of negative number
by replacing it with a multiplication. Said multiplication can't
overflow an int32_t because lpc_coefs is limited to 16 bit precision.
Fixes the FACE-test acodec-ra144 as well as part of #8217.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit
e3fb9af6f1353f30855eaa1cbd5befaf06e303b8)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>