utils: move base64 length compute to macros

This allows us to initialize data for static variables, such as uuid

ut.h

@@ -1073,17 +1073,10 @@ int base64decode(unsigned char *out,unsigned char *in,int len);
 void word64encode(unsigned char *out, unsigned char *in, int inlen);
 int word64decode(unsigned char *out, unsigned char *in, int len);
 
-static inline int calc_base64_encode_len(int len)
-{
-	return (len/3 + (len%3?1:0))*4;
-}
-#define calc_word64_encode_len calc_base64_encode_len
-
-static inline int calc_max_base64_decode_len(int len)
-{
-	return len*3/4;
-}
+#define calc_base64_encode_len(_l) (((_l)/3 + ((_l)%3?1:0))*4)
+#define calc_max_base64_decode_len(_l) ((_l)*3/4)
 
+#define calc_word64_encode_len calc_base64_encode_len
 #define calc_max_word64_decode_len calc_max_base64_decode_len