scsi: lpfc: Use unsigned type for num_sge

LUNs going into "failed ready running" state observed on >1T and on even
numbers of size (2T, 4T, 6T, 8T and 10T). The issue occurs when DIF is
enabled at the host.

The kernel logs:

  Cannot setup S/G List for HBAIO segs 1/1 SGL 512 SCSI 256: 3 0

The host lpfc driver is failing to setup scatter/gather list (protection
data) for the I/Os.

The return type lpfc_bg_setup_sgl()/lpfc_bg_setup_sgl_prot() causes the
compiler to remove the most significant bit. Use an unsigned type instead.

Signed-off-by: Hannes Reinecke <hare@suse.de>
[dwagner: added commit message]
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Link: https://lore.kernel.org/r/20231220162658.12392-1-dwagner@suse.de
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: hreinecke

drivers/scsi/lpfc/lpfc_scsi.c

@@ -1918,16 +1918,16 @@ lpfc_bg_setup_bpl_prot(struct lpfc_hba *phba, struct scsi_cmnd *sc,
  *
  * Returns the number of SGEs added to the SGL.
  **/
-static int
+static uint32_t
 lpfc_bg_setup_sgl(struct lpfc_hba *phba, struct scsi_cmnd *sc,
 		struct sli4_sge *sgl, int datasegcnt,
 		struct lpfc_io_buf *lpfc_cmd)
 {
 	struct scatterlist *sgde = NULL; /* s/g data entry */
 	struct sli4_sge_diseed *diseed = NULL;
 	dma_addr_t physaddr;
-	int i = 0, num_sge = 0, status;
-	uint32_t reftag;
+	int i = 0, status;
+	uint32_t reftag, num_sge = 0;
 	uint8_t txop, rxop;
 #ifdef CONFIG_SCSI_LPFC_DEBUG_FS
 	uint32_t rc;
@@ -2099,7 +2099,7 @@ lpfc_bg_setup_sgl(struct lpfc_hba *phba, struct scsi_cmnd *sc,
  *
  * Returns the number of SGEs added to the SGL.
  **/
-static int
+static uint32_t
 lpfc_bg_setup_sgl_prot(struct lpfc_hba *phba, struct scsi_cmnd *sc,
 		struct sli4_sge *sgl, int datacnt, int protcnt,
 		struct lpfc_io_buf *lpfc_cmd)
@@ -2123,8 +2123,8 @@ lpfc_bg_setup_sgl_prot(struct lpfc_hba *phba, struct scsi_cmnd *sc,
 	uint32_t rc;
 #endif
 	uint32_t checking = 1;
-	uint32_t dma_offset = 0;
-	int num_sge = 0, j = 2;
+	uint32_t dma_offset = 0, num_sge = 0;
+	int j = 2;
 	struct sli4_hybrid_sgl *sgl_xtra = NULL;
 
 	sgpe = scsi_prot_sglist(sc);