Fix several warnings

A small, nonexhaustive set of warning fixes. The DiscIO Volume change
is a workaround for a GCC bug [1] that causes returning an unengaged
std::optional to emit annoying -Wmaybe-uninitialized warnings.
This last change alone fixes pages upon pages of warnings since
Volume.h is included from several files.

-Wstringop-truncation is another irrelevant warning for us, but
unfortunately there seems to be no way to disable it without
adding ugly pragmas wherever the warning appears.

1 files changed, 0 insertions, 2 deletions

diff --git a/Source/Core/DiscIO/VolumeVerifier.cpp b/Source/Core/DiscIO/VolumeVerifier.cpp
index 15d53f62a1..b6b7ea4901 100644
--- a/Source/Core/DiscIO/VolumeVerifier.cpp
+++ b/Source/Core/DiscIO/VolumeVerifier.cpp
@@ -88,11 +88,9 @@ void RedumpVerifier::Start(const Volume& volume)
       return {};
     }
 
-    DownloadStatus status;
     {
       std::lock_guard lk(download_state->mutex);
       download_state->status = DownloadDatfile(system, download_state->status);
-      status = download_state->status;
     }
 
     switch (download_state->status)