net: lan743x: Initialize eth_syslock spinlock before use

In the Linux kernel, the following vulnerability has been resolved: net: lan743x: Initialize eth_syslock spinlock before use lan743x_hardware_init() calls pci11x1x_strap_get_status() during the PCI11x1x probe sequence. That helper acquires the Ethernet subsystem hardware lock via lan743x_hs_syslock_acquire(), which relies on adapter->eth_syslock_spinlock to serialize access. The spinlock is currently initialized only after the strap status is read. With CONFIG_DEBUG_SPINLOCK enabled, taking the zeroed initialized spinlock can trip the spinlock debug check. Fix by initializing adapter->eth_syslock_spinlock before reading the strap status so the probe path never attempts to lock an uninitialized spinlock.