jrev/xvid: hardcode use of C put/add_pixels_clamped.

This removes the last use of the ff_put/add_pixels_clamped global
function pointers, and as such they are removed.

This patch has a negative effect on performance on MIPS, since there's
a SIMD-optimized put/add_pixels_clamped, but no xvid or jrev. From a
code maintenance point of view, that is probably acceptable.

Because the global function pointers are removed, this fixes the following
tsan warnings when running e.g. fate-dnxhr-parse:

WARNING: ThreadSanitizer: data race (pid=29917)
  Write of size 8 at 0x0000025b12d8 by thread T2 (mutexes: write M1543):
    #0 ff_idctdsp_init src/libavcodec/idctdsp.c:313 (ffmpeg+0x00000044b68e)
[..]
  Previous write of size 8 at 0x0000025b12d8 by thread T1 (mutexes: write M1541):
    #0 ff_idctdsp_init src/libavcodec/idctdsp.c:313 (ffmpeg+0x00000044b68e)

1 files changed, 4 insertions, 2 deletions

diff --git a/libavcodec/idctdsp.h b/libavcodec/idctdsp.h
index f9ba6c3..26221f6 100644
--- a/libavcodec/idctdsp.h
+++ b/libavcodec/idctdsp.h
@@ -97,8 +97,10 @@ typedef struct IDCTDSPContext {
     enum idct_permutation_type perm_type;
 } IDCTDSPContext;
 
-extern void (*ff_put_pixels_clamped)(const int16_t *block, uint8_t *pixels, ptrdiff_t line_size);
-extern void (*ff_add_pixels_clamped)(const int16_t *block, uint8_t *pixels, ptrdiff_t line_size);
+void ff_put_pixels_clamped_c(const int16_t *block, uint8_t *av_restrict pixels,
+                             ptrdiff_t line_size);
+void ff_add_pixels_clamped_c(const int16_t *block, uint8_t *av_restrict pixels,
+                             ptrdiff_t line_size);
 
 void ff_idctdsp_init(IDCTDSPContext *c, AVCodecContext *avctx);