avutil/integer: Use '|' instead of '+' where it is more natural

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavutil/integer.c

@@ -104,7 +104,7 @@ AVInteger av_shr_i(AVInteger a, int s){
         unsigned int index= i + (s>>4);
         unsigned int v=0;
         if (index + 1 < AV_INTEGER_SIZE) v  = a.v[index + 1] * (1U << 16);
-        if(index  <AV_INTEGER_SIZE) v+= a.v[index  ];
+        if (index     < AV_INTEGER_SIZE) v |= a.v[index];
         out.v[i]= v >> (s&15);
     }
     return out;
@@ -161,6 +161,6 @@ int64_t av_i2int(AVInteger a){
     uint64_t out = a.v[3];
 
     for (int i = 2; i >= 0; i--)
-        out = (out<<16) + a.v[i];
+        out = (out << 16) | a.v[i];
     return out;
 }