bnxt_en: Fix memory leak in bnxt_hwrm_get_rings()

bnxt_hwrm_get_rings() can abort and return error when there are not
enough ring resources.  It aborts without releasing the HWRM DMA buffer,
causing a dma_pool_destroy warning when the driver is unloaded:

bnxt_en 0000:99:00.0: dma_pool_destroy bnxt_hwrm, 000000005b089ba8 busy

Fixes: f1e50b27 ("bnxt_en: Fix trimming of P5 RX and TX rings")
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/20240117234515.226944-3-michael.chan@broadcom.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -6926,7 +6926,7 @@ static int bnxt_hwrm_get_rings(struct bnxt *bp)
 			if (cp < (rx + tx)) {
 				rc = __bnxt_trim_rings(bp, &rx, &tx, cp, false);
 				if (rc)
-					return rc;
+					goto get_rings_exit;
 				if (bp->flags & BNXT_FLAG_AGG_RINGS)
 					rx <<= 1;
 				hw_resc->resv_rx_rings = rx;
@@ -6938,8 +6938,9 @@ static int bnxt_hwrm_get_rings(struct bnxt *bp)
 		hw_resc->resv_cp_rings = cp;
 		hw_resc->resv_stat_ctxs = stats;
 	}
+get_rings_exit:
 	hwrm_req_drop(bp, req);
-	return 0;
+	return rc;
 }
 
 int __bnxt_hwrm_get_tx_rings(struct bnxt *bp, u16 fid, int *tx_rings)