exec/tswap: Massage target_needs_bswap() definition

Invert target_needs_bswap() comparison to match the
COMPILING_PER_TARGET definition (2 lines upper).

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20241010175246.15779-2-philmd@linaro.org>

include/exec/tswap.h

@@ -28,7 +28,7 @@ bool target_words_bigendian(void);
 #ifdef COMPILING_PER_TARGET
 #define target_needs_bswap()  (HOST_BIG_ENDIAN != TARGET_BIG_ENDIAN)
 #else
-#define target_needs_bswap()  (target_words_bigendian() != HOST_BIG_ENDIAN)
+#define target_needs_bswap()  (HOST_BIG_ENDIAN != target_words_bigendian())
 #endif /* COMPILING_PER_TARGET */
 
 static inline uint16_t tswap16(uint16_t s)