swscale/ops: nuke SwsComps.unused

Finally, remove the last relic of this accursed design mistake.

Signed-off-by: Niklas Haas <git@haasn.dev>

libswscale/ops.c

@@ -581,10 +581,7 @@ void ff_sws_op_list_update_comps(SwsOpList *ops)
             break;
         }
 
-        for (int i = 0; i < 4; i++) {
-            need_out[i] = need_in[i];
-            op->comps.unused[i] = !need_in[i];
-        }
+        memcpy(need_out, need_in, sizeof(need_in));
     }
 }
 

libswscale/ops.h

@@ -108,7 +108,6 @@ typedef enum SwsCompFlags {
 
 typedef struct SwsComps {
     SwsCompFlags flags[4]; /* knowledge about (output) component contents */
-    bool unused[4]; /* which input components are definitely unused */
 
     /* Keeps track of the known possible value range, or {0, 0} for undefined
      * or (unknown range) floating point inputs */