avifCodecDecodeInputGetSamples: check for overflow

Check if the addition sampleOffset + sampleSize would overflow in
avifCodecDecodeInputGetSamples().

src/read.c

diff --git a/src/read.c b/src/read.c
index e1bde74..d877e13 100644
--- a/src/read.c
+++ b/src/read.c
@@ -366,6 +366,9 @@
             sample->size = sampleSize;
             sample->sync = AVIF_FALSE; // to potentially be set to true following the outer loop
 
+            if (sampleSize > UINT64_MAX - sampleOffset) {
+                return AVIF_FALSE;
+            }
             if (sizeHint && ((sampleOffset + sampleSize) > (uint64_t)sizeHint)) {
                 return AVIF_FALSE;
             }