avcodec/motionpixels: Mark 2 functions as always_inline

Fixes: Timeout (30sec -> 25sec)
Fixes: 17050/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOTIONPIXELS_fuzzer-5719149803732992

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 017884bdc3)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/motionpixels.c

@@ -171,7 +171,7 @@ static int mp_read_codes_table(MotionPixelsContext *mp, GetBitContext *gb)
    return 0;
 }
 
-static int mp_gradient(MotionPixelsContext *mp, int component, int v)
+static av_always_inline int mp_gradient(MotionPixelsContext *mp, int component, int v)
 {
     int delta;
 
@@ -196,7 +196,7 @@ static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const Yuv
     *(uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2] = color;
 }
 
-static int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
+static av_always_inline int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
 {
     int i;