kernel32: Remove extraneous braces from switch statement

[Andrew Talbot]

Changelog:
    kernel32: Remove extraneous braces from switch statement.

diff --git a/dlls/kernel32/volume.c b/dlls/kernel32/volume.c
index e2b03a2..216dd17 100644
--- a/dlls/kernel32/volume.c
+++ b/dlls/kernel32/volume.c
@@ -585,12 +585,10 @@ static DWORD VOLUME_GetSuperblockSerial( const UNICODE_STRING *device, HANDLE ha
     case FS_FAT32:
         return GETLONG( superblock, 0x33 );
     case FS_UDF:
-        {
             if (!VOLUME_ReadCDBlock(handle, block, 257*BLOCK_SIZE))
                 break;
             superblock = block;
             /* fallthrough */
-        }
     case FS_ISO9660:
         {
             BYTE sum[4];