scsi: lpfc: Turn lpfc_queue q_pgs into a flexible array

The q_pgs pointer was assigned to point at the trailing memory allocated
past the struct. Convert it to a proper C99 flexible array member and
use struct_size() for the allocation.

Assisted-by: Claude:Opus-4.7
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Justin Tee <justin.tee@broadcom.com>
Link: https://patch.msgid.link/20260523050241.190239-1-rosenp@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: neheb

drivers/scsi/lpfc/lpfc_sli.c

@@ -15875,7 +15875,7 @@ lpfc_sli4_queue_alloc(struct lpfc_hba *phba, uint32_t page_size,
 	if (pgcnt > phba->sli4_hba.pc_sli4_params.wqpcnt)
 		pgcnt = phba->sli4_hba.pc_sli4_params.wqpcnt;
 
-	queue = kzalloc_node(sizeof(*queue) + (sizeof(void *) * pgcnt),
+	queue = kzalloc_node(struct_size(queue, q_pgs, pgcnt),
 			     GFP_KERNEL, cpu_to_node(cpu));
 	if (!queue)
 		return NULL;
@@ -15892,7 +15892,6 @@ lpfc_sli4_queue_alloc(struct lpfc_hba *phba, uint32_t page_size,
 	 * resources, the free routine needs to know what was allocated.
 	 */
 	queue->page_count = pgcnt;
-	queue->q_pgs = (void **)&queue[1];
 	queue->entry_cnt_per_pg = hw_page_size / entry_size;
 	queue->entry_size = entry_size;
 	queue->entry_count = entry_count;

drivers/scsi/lpfc/lpfc_sli4.h

@@ -280,9 +280,10 @@ struct lpfc_queue {
 	uint64_t isr_timestamp;
 	struct lpfc_queue *assoc_qp;
 	struct list_head _poll_list;
-	void **q_pgs;	/* array to index entries per page */
 
 	enum lpfc_poll_mode poll_mode;
+
+	void *q_pgs[];	/* array to index entries per page */
 };
 
 struct lpfc_sli4_link {