Add missing comment for the offset argument of tokenize. Add error checko on the offset.

libc/inc/string.h

@@ -174,6 +174,7 @@ char *strtok_r(char *str, const char *delim, char **saveptr);
 /// parsed token in buffer. The pointer `string` will be modified.
 /// @param string cursor used to parse the string, it will be modified.
 /// @param separators the list of separators we are using.
+/// @param offset the offset character from which we start extracting the next token.
 /// @param buffer the buffer where we save the parsed token.
 /// @param buflen the length of the buffer.
 /// @return 1 if we still have things to parse, 0 if we finished parsing.

libc/inc/sys/unistd.h

@@ -61,7 +61,7 @@ int unlink(const char *path);
 int symlink(const char *linkname, const char *path);
 
 /// @brief Read the symbolic link, if present.
-/// @param file the file for which we want to read the symbolic link information.
+/// @param path the file for which we want to read the symbolic link information.
 /// @param buffer the buffer where we will store the symbolic link path.
 /// @param bufsize the size of the buffer.
 /// @return The number of read characters on success, -1 otherwise and errno is set to indicate the error.