uuid: Use const char * where possible

Update the arguments of these functions so they can be called from code
which uses constant strings.
Signed-off-by: NSimon Glass <sjg@chromium.org>

include/uuid.h

@@ -35,11 +35,13 @@ struct uuid {
 #define UUID_VARIANT		0x1
 
 int uuid_str_valid(const char *uuid);
-int uuid_str_to_bin(char *uuid_str, unsigned char *uuid_bin, int str_format);
-void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format);
+int uuid_str_to_bin(const char *uuid_str, unsigned char *uuid_bin,
+		    int str_format);
+void uuid_bin_to_str(const unsigned char *uuid_bin, char *uuid_str,
+		     int str_format);
 #ifdef CONFIG_PARTITION_TYPE_GUID
 int uuid_guid_get_bin(const char *guid_str, unsigned char *guid_bin);
-int uuid_guid_get_str(unsigned char *guid_bin, char *guid_str);
+int uuid_guid_get_str(const unsigned char *guid_bin, char *guid_str);
 #endif
 void gen_rand_uuid(unsigned char *uuid_bin);
 void gen_rand_uuid_str(char *uuid_str, int str_format);

lib/uuid.c

@@ -121,7 +121,7 @@ int uuid_guid_get_bin(const char *guid_str, unsigned char *guid_bin)
  * @param guid_bin - pointer to string with partition type guid [16B]
  * @param guid_str - pointer to allocated partition type string [7B]
  */
-int uuid_guid_get_str(unsigned char *guid_bin, char *guid_str)
+int uuid_guid_get_str(const unsigned char *guid_bin, char *guid_str)
 {
 	int i;
 
@@ -143,7 +143,8 @@ int uuid_guid_get_str(unsigned char *guid_bin, char *guid_str)
  * @param uuid_bin - pointer to allocated array for big endian output [16B]
  * @str_format     - UUID string format: 0 - UUID; 1 - GUID
  */
-int uuid_str_to_bin(char *uuid_str, unsigned char *uuid_bin, int str_format)
+int uuid_str_to_bin(const char *uuid_str, unsigned char *uuid_bin,
+		    int str_format)
 {
 	uint16_t tmp16;
 	uint32_t tmp32;
@@ -194,7 +195,8 @@ int uuid_str_to_bin(char *uuid_str, unsigned char *uuid_bin, int str_format)
  * @str_format:		bit 0: 0 - UUID; 1 - GUID
  *			bit 1: 0 - lower case; 2 - upper case
  */
-void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
+void uuid_bin_to_str(const unsigned char *uuid_bin, char *uuid_str,
+		     int str_format)
 {
 	const u8 uuid_char_order[UUID_BIN_LEN] = {0, 1, 2, 3, 4, 5, 6, 7, 8,
 						  9, 10, 11, 12, 13, 14, 15};