doc: kernel: fix k_poll example

Fix `k_poll()` loop example by using separate `if` blocks instead of
`if`-`else`-chain to ensure all events are handled, even if multiple are
active at the same time.

Signed-off-by: Cla Mattia Galliard <[email protected]>

Author: Cla Mattia Galliard

doc/kernel/services/polling.rst

@@ -187,13 +187,16 @@ to :c:macro:`K_POLL_STATE_NOT_READY` by the user.
             rc = k_poll(events, ARRAY_SIZE(events), K_FOREVER);
             if (events[0].state == K_POLL_STATE_SEM_AVAILABLE) {
                 k_sem_take(events[0].sem, 0);
-            } else if (events[1].state == K_POLL_STATE_FIFO_DATA_AVAILABLE) {
+            }
+            if (events[1].state == K_POLL_STATE_FIFO_DATA_AVAILABLE) {
                 data = k_fifo_get(events[1].fifo, 0);
                 // handle data
-            } else if (events[2].state == K_POLL_STATE_MSGQ_DATA_AVAILABLE) {
+            }
+            if (events[2].state == K_POLL_STATE_MSGQ_DATA_AVAILABLE) {
                 ret = k_msgq_get(events[2].msgq, buf, K_NO_WAIT);
                 // handle data
-            } else if (events[3].state == K_POLL_STATE_PIPE_DATA_AVAILABLE) {
+            }
+            if (events[3].state == K_POLL_STATE_PIPE_DATA_AVAILABLE) {
                 ret = k_pipe_get(events[3].pipe, buf, bytes_to_read, &bytes_read, min_xfer, K_NO_WAIT);
                 // handle data
             }