KTX2: fix wrong error message for oversized level uncompressed length

The sanity check on a level's m_uncompressed_byte_length (>= 2 GiB)
logged "Invalid level offset (too large)", which names the wrong field.
Correct it to "Invalid level uncompressed byte length (too large)".

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

transcoder/basisu_transcoder.cpp

diff --git a/transcoder/basisu_transcoder.cpp b/transcoder/basisu_transcoder.cpp
index 2e413ed..b22d487 100644
--- a/transcoder/basisu_transcoder.cpp
+++ b/transcoder/basisu_transcoder.cpp
@@ -19965,7 +19965,7 @@
 			
 			if (m_levels[i].m_uncompressed_byte_length.get_uint64() >= MAX_SANE_LEVEL_UNCOMP_SIZE)
 			{
-				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level offset (too large)\n");
+				BASISU_DEVEL_ERROR("ktx2_transcoder::init: Invalid level uncompressed byte length (too large)\n");
 				return false;
 			}