Fix spelling mistake

src/units.c

@@ -56,7 +56,7 @@ void units_init_cgs(struct unit_system* us) {
 
 /**
  * @brief Initialises the unit_system structure with the constants given in
- * rhe parameter file.
+ * the parameter file.
  *
  * @param us The unit_system to initialize.
  * @param params The parsed parameter file.
@@ -81,7 +81,7 @@ void units_init(struct unit_system* us, const struct swift_params* params,
 
 /**
  * @brief Initialises the unit_system structure with the constants given in
- * rhe parameter file. Uses a default if the values are not present in the file.
+ * the parameter file. Uses a default if the values are not present in the file.
  *
  * @param us The unit_system to initialize.
  * @param params The parsed parameter file.