Get rid of warning 'ISO C++11 does not allow conversion from string literal to char *' in sftp_canonicalize_path

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
(cherry picked from commit ec784ca901)

kftpgrabber/src/misc/libs/ssh/libssh.h

@@ -103,7 +103,7 @@ const char *ssh_copyright();
 
 /* You can use these functions, they won't change */
 /* makestring returns a newly allocated string from a char * ptr */
-STRING *string_from_char(char *what);
+STRING *string_from_char(const char *what);
 /* it returns the string len in host byte orders. str->size is big endian warning ! */
 int string_len(STRING *str);
 STRING *string_new(u32 size);

kftpgrabber/src/misc/libs/ssh/sftp.c

@@ -1161,7 +1161,7 @@ int sftp_setstat(SFTP_SESSION *sftp, char *file, SFTP_ATTRIBUTES *attr) {
 }
 
 /* another code written by Nick */
-char *sftp_canonicalize_path(SFTP_SESSION *sftp, char *path)
+char *sftp_canonicalize_path(SFTP_SESSION *sftp, const char *path)
 {
 	u32 id = sftp_get_new_id(sftp);
 	BUFFER *buffer = buffer_new();

kftpgrabber/src/misc/libs/ssh/sftp.h

@@ -136,7 +136,7 @@ int sftp_rmdir(SFTP_SESSION *sftp, char *directory);
 int sftp_mkdir(SFTP_SESSION *sftp, char *directory, SFTP_ATTRIBUTES *attr);
 int sftp_rename(SFTP_SESSION *sftp, char *original, char *newname);
 int sftp_setstat(SFTP_SESSION *sftp, char *file, SFTP_ATTRIBUTES *attr);
-char *sftp_canonicalize_path(SFTP_SESSION *sftp, char *path);
+char *sftp_canonicalize_path(SFTP_SESSION *sftp, const char *path);
 
 /* SFTP commands and constants */
 #define SSH_FXP_INIT 1

kftpgrabber/src/misc/libs/ssh/string.c

@@ -36,7 +36,7 @@ void string_fill(STRING *str,void *data,int len){
     memcpy(str->string,data,len);
 }
 
-STRING *string_from_char(char *what){
+STRING *string_from_char(const char *what){
 	STRING *ptr;
 	int len=strlen(what);
 	ptr=malloc(4 + len);