add bracket around the argument (fixes compilation error with ICL)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/libmpcodecs/vf_mcdeint.c

@@ -125,13 +125,13 @@ static void filter(struct vf_priv_s *p, uint8_t *dst[3], uint8_t *src[3], int ds
                         int temp= filp[0];
 
 #define CHECK(j)\
-    {   int score= ABS(srcp[-srcs-1+j] - srcp[+srcs-1-j])\
-                 + ABS(srcp[-srcs  +j] - srcp[+srcs  -j])\
-                 + ABS(srcp[-srcs+1+j] - srcp[+srcs+1-j]);\
+    {   int score= ABS(srcp[-srcs-1+(j)] - srcp[+srcs-1-(j)])\
+                 + ABS(srcp[-srcs  +(j)] - srcp[+srcs  -(j)])\
+                 + ABS(srcp[-srcs+1+(j)] - srcp[+srcs+1-(j)]);\
         if(score < spatial_score){\
             spatial_score= score;\
-            diff0= filp[-fils+j] - srcp[-srcs+j];\
-            diff1= filp[+fils-j] - srcp[+srcs-j];
+            diff0= filp[-fils+(j)] - srcp[-srcs+(j)];\
+            diff1= filp[+fils-(j)] - srcp[+srcs-(j)];
 
                         CHECK(-1) CHECK(-2) }} }}
                         CHECK( 1) CHECK( 2) }} }}