Remove function macro UINT8_C() from AERON_DATA_HEADER_UNFRAGMENTED d…

…efinition. (#1685)

The defined values are not evaluated by the preprocessor before being
stringified which causes issues with some libc implementations.

The individual flags are already the correct type so the type is still
correct.

aeron-client/src/main/c/protocol/aeron_udp_protocol.h

@@ -181,7 +181,7 @@ int aeron_udp_protocol_group_tag(aeron_status_message_header_t *sm, int64_t *gro
 #define AERON_DATA_HEADER_END_FLAG (UINT8_C(0x40))
 #define AERON_DATA_HEADER_EOS_FLAG (UINT8_C(0x20))
 
-#define AERON_DATA_HEADER_UNFRAGMENTED (UINT8_C(AERON_DATA_HEADER_BEGIN_FLAG | AERON_DATA_HEADER_END_FLAG))
+#define AERON_DATA_HEADER_UNFRAGMENTED (AERON_DATA_HEADER_BEGIN_FLAG | AERON_DATA_HEADER_END_FLAG)
 
 #define AERON_DATA_HEADER_DEFAULT_RESERVED_VALUE (INT64_C(0))