Update src/_imaging.c

Un-inline the accumulative ternary expression in the second `for` loop, in favor of a more straightforward `if`.

Co-Authored-By: fish2000 <fish2000@users.noreply.github.com>

src/_imaging.c

@@ -1298,7 +1298,9 @@ _entropy(ImagingObject* self, PyObject* args)
     fentropy = 0.0;
     for (idx = 0; idx < length; idx++) {
         p = (double)h->histogram[idx] / fsum;
-        fentropy += p != 0.0 ? (p * log(p) * M_LOG2E) : 0.0;
+        if (p != 0.0) {
+            fentropy += p * log(p) * M_LOG2E;
+        }
     }
 
     /* Finally, allocate a PyObject* for return */