update type names

naming convention: Type names should start with a Capital letter (after the prefix)

tests/fuzz/simple_round_trip.c

@@ -34,7 +34,7 @@ static size_t getDecompressionMargin(void const* compressed, size_t cSize, size_
         /* The macro should be correct in this case, but it may be smaller
          * because of e.g. block splitting, so take the smaller of the two.
          */
-        ZSTD_frameHeader zfh;
+        ZSTD_FrameHeader zfh;
         size_t marginM;
         FUZZ_ZASSERT(ZSTD_getFrameHeader(&zfh, compressed, cSize));
         if (maxBlockSize == 0) {

tests/fuzz/zstd_frame_info.c

@@ -21,7 +21,7 @@
 
 int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
 {
-    ZSTD_frameHeader zfh;
+    ZSTD_FrameHeader zfh;
     if (size == 0) {
         src = NULL;
    }