fixup! fix(core): validate start + size for buffer ops in more places

Author: ErichDonGubler

wgpu-core/src/resource.rs

@@ -741,7 +741,7 @@ impl Buffer {
         let map_state = &*self.map_state.lock();
         match *map_state {
             BufferMapState::Init { ref staging_buffer } => {
-                if offset >= self.size {
+                if offset > self.size {
                     return Err(BufferAccessError::MapStartOffsetOverrun {
                         offset,
                         buffer_size: self.size,