rename my_string to input_str for better naming

challenge/challenge.c

@@ -5,15 +5,15 @@
 int main() {
     int ret;
     size_t nbytes = 0;
-    char *my_string = NULL;
+    char *input_str = NULL;
     char *password = "23door42\n";
 
     puts("Please enter Password: ");
-    ret = getline(&my_string, &nbytes, stdin);
+    ret = getline(&input_str, &nbytes, stdin);
 
     if (ret == -1) {
         puts("Error");
-    } else if (strcmp(my_string, password) == 0) {
+    } else if (strcmp(input_str, password) == 0) {
         puts("Success");
         ret = 0;
     } else {
@@ -21,6 +21,6 @@ int main() {
         ret = -1;
     }
 
-    free(my_string);
+    free(input_str);
     return ret;
 }