staging: fbtft: Use ARRAY_SIZE() to get argument count

The ARRAY_SIZE(foo) macro should be preferred over sizeof operator
based computation such as sizeof(foo)/sizeof(foo[0]) for finding
number of elements in an array. Issue identified using coccicheck.

Signed-off-by: Deepak R Varma <drv@mailo.com>

drivers/staging/fbtft/fbtft.h

@@ -231,7 +231,7 @@ struct fbtft_par {
 	bool polarity;
 };
 
-#define NUMARGS(...)  (sizeof((int[]){__VA_ARGS__}) / sizeof(int))
+#define NUMARGS(...)  ARRAY_SIZE(((int[]){ __VA_ARGS__ }))
 
 #define write_reg(par, ...)                                            \
 	((par)->fbtftops.write_register(par, NUMARGS(__VA_ARGS__), __VA_ARGS__))