BUG/MEDIUM: sample: Fix adjusting size in word converter

Adjust the size of the sample buffer before we change the "area"
pointer. Otherwise, we end up not changing the size, because the area
pointer is already the same as "start" before we compute the difference
between the two.

This is similar to the change in b28430591d
but for the word converter instead of field.

src/sample.c

@@ -2596,13 +2596,14 @@ found:
 	if (!smp->data.u.str.data)
 		return 1;
 
-	smp->data.u.str.area = start;
 
 	/* Compute remaining size if needed
            Note: smp->data.u.str.size cannot be set to 0 */
 	if (smp->data.u.str.size)
 		smp->data.u.str.size -= start - smp->data.u.str.area;
 
+	smp->data.u.str.area = start;
+
 	return 1;
 }