lib: xpc: fix overlapping variable uses in xpc_string_t

lib/libxpc/string.c

@@ -47,14 +47,10 @@ xpc_status_t xpc_string_write(
 		to_write = s->s_max - 1;
 	}
 
-	kern_status_t status
-		= xpc_msg_write(s->s_origin, s->s_offset, in, to_write);
-	if (status != KERN_OK) {
-		return status;
-	}
-
-	/* TODO */
-	*nr_written = to_write;
-
-	return KERN_OK;
+	return xpc_msg_write(
+		s->s_origin,
+		s->s_offset,
+		in,
+		to_write,
+		nr_written);
 }