Fix some more LFS_TRACE format specifiers

[geky]

More printf warnings in LFS_TRACE found by @stefano-zanotti:

• block_cycles is signed and should use PRId32
• flags is signed (which is a bit weird) and should be cast for %x

Unfortunately exactly what PRI* expands to is dependant on both the compiler and the underlying architecture, so I don't think it's possible for us to catch these mistakes with CI...

Found by @stefano-zanotti See https://github.com/littlefs-project/littlefs/issues/982 for more info

[geky-bot]

Tests passed ✓, Code: 17064 B (+0.0%), Stack: 1440 B (+0.0%), Structs: 812 B (+0.0%)

| | Code | Stack | Structs | | Coverage | |:--|-----:|------:|--------:|:--|---------:| | Default | 17064 B (+0.0%) | 1440 B (+0.0%) | 812 B (+0.0%) | Lines | 2394/2574 lines (-0.0%) | | Readonly | 6194 B (+0.0%) | 448 B (+0.0%) | 812 B (+0.0%) | Branches | 1245/1584 branches (+0.0%) | | Threadsafe | 17924 B (+0.0%) | 1440 B (+0.0%) | 820 B (+0.0%) | | **Benchmarks** | | Multiversion | 17124 B (+0.0%) | 1440 B (+0.0%) | 816 B (+0.0%) | Readed | 29369693876 B (+0.0%) | | Migrate | 18760 B (+0.0%) | 1744 B (+0.0%) | 816 B (+0.0%) | Proged | 1482874766 B (+0.0%) | | Error-asserts | 17748 B (+0.0%) | 1432 B (+0.0%) | 812 B (+0.0%) | Erased | 1568888832 B (+0.0%) |