scsi: qla2xxx: Sanitize payload size to prevent member overflow

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Sanitize payload size to prevent member overflow In qla27xx_copy_fpin_pkt() and qla27xx_copy_multiple_pkt(), the frame_size reported by firmware is used to calculate the copy length into item->iocb. However, the iocb member is defined as a fixed-size 64-byte array within struct purex_item. If the reported frame_size exceeds 64 bytes, subsequent memcpy calls will overflow the iocb member boundary. While extra memory might be allocated, this cross-member write is unsafe and triggers warnings under CONFIG_FORTIFY_SOURCE. Fix this by capping total_bytes to the size of the iocb member (64 bytes) before allocation and copying. This ensures all copies remain within the bounds of the destination structure member.