fate-bprint: try to workaround platform specific value.

this should fix some fate failures
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavutil/bprint.c

@@ -211,7 +211,7 @@ int main(void)
 
     av_bprint_init(&b, 0, 1);
     bprint_pascal(&b, 25);
-    printf("Long text in automatic buffer: %zu/%u\n", strlen(b.str), b.len);
+    printf("Long text in automatic buffer: %zu/%u\n", strlen(b.str)/8*8, b.len);
     /* Note that the size of the automatic buffer is arch-dependant. */
 
     av_bprint_init(&b, 0, 0);

tests/ref/fate/bprint

@@ -9,6 +9,6 @@ Short text in unlimited buffer: 174/174
 Long text in unlimited buffer: 2834/2834
 Long text in limited buffer: 2047/2834
 Short text in automatic buffer: 174/174
-Long text in automatic buffer: 1003/2834
+Long text in automatic buffer: 1000/2834
 Long text count only buffer: 0/2834
 Long text count only buffer: 255/2834