page_pool: fix documentation typos

Correct grammar for better readability.

Signed-off-by: Randy Dunlap <[e-mail]>
Cc: Jesper Dangaard Brouer <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
Acked-by: Ilias Apalodimas <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

include/net/page_pool/helpers.h

···
  * page_pool_alloc_pages() call.  Drivers should use
  * page_pool_dev_alloc_pages() replacing dev_alloc_pages().
  *
- * API keeps track of in-flight pages, in order to let API user know
+ * The API keeps track of in-flight pages, in order to let API users know
  * when it is safe to free a page_pool object.  Thus, API users
  * must call page_pool_put_page() to free the page, or attach
- * the page to a page_pool-aware objects like skbs marked with
+ * the page to a page_pool-aware object like skbs marked with
  * skb_mark_for_recycle().
  *
- * API user must call page_pool_put_page() once on a page, as it
+ * API users must call page_pool_put_page() once on a page, as it
  * will either recycle the page, or in case of refcnt > 1, it will
  * release the DMA mapping and in-flight state accounting.
  */