Add error handling in lock initialization in the Xtensa port #67

All 475 tests pass in 2m 21s

475 tests ±0 475 ✔️ ±0 2m 21s ⏱️ +2s
    5 suites ±0     0 💤 ±0
    5 files ±0     0 ❌ ±0

Results for commit e92e750. ± Comparison against earlier commit 8fbd23d.