[NFC][TSan] Check IsFiredSuppression before ScopedReport in ReportErrnoSpoiling (#228811)
Check IsFiredSuppression(ctx, ReportTypeErrnoInSignal, stack) and return
early before constructing ScopedReport in ReportErrnoSpoiling (matching
SignalUnsafeCall and ReportRace). This avoids acquiring
ScopedErrorReportLock and ThreadRegistryLock for already-suppressed
reports.
Assisted-by: Gemini