BINARYBUFFER: review scope of data and functions

Add "static" qualifier to private data and functions.

Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>

src/helper/binarybuffer.c

@@ -27,7 +27,7 @@
 #include "log.h"
 #include "binarybuffer.h"
 
-const unsigned char bit_reverse_table256[] =
+static const unsigned char bit_reverse_table256[] =
 {
   0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
   0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
@@ -161,7 +161,7 @@ uint32_t flip_u32(uint32_t value, unsigned int num)
 	return c;
 }
 
-int ceil_f_to_u32(float x)
+static int ceil_f_to_u32(float x)
 {
 	if (x < 0)	/* return zero for negative numbers */
 		return 0;