more spelling mistakes

src/modules/systemlib/mixer/mixer.h

@@ -481,7 +481,7 @@ public:
 	 *				compared to thrust.
 	 * @param yaw_wcale		Scaling factor applied to yaw inputs compared
 	 *				to thrust.
-	 * @param idle_speed		Minumum rotor control output value; usually
+	 * @param idle_speed		Minimum rotor control output value; usually
 	 *				tuned to ensure that rotors never stall at the
 	 * 				low end of their control range.
 	 */

src/modules/systemlib/up_cxxinitialize.c

@@ -118,7 +118,7 @@ extern uint32_t _etext;
  *   This function should then be called in the application-specific
  *   user_start logic in order to perform the C++ initialization.  NOTE
  *   that no component of the core NuttX RTOS logic is involved; This
- *   function defintion only provides the 'contract' between application
+ *   function definition only provides the 'contract' between application
  *   specific C++ code and platform-specific toolchain support
  *
  ***************************************************************************/

src/modules/systemlib/uthash/doc/userguide.txt

@@ -1058,7 +1058,7 @@ always used with the `users_by_name` hash table).
 
 Several sort orders
 ~~~~~~~~~~~~~~~~~~~
-It comes as no suprise that two hash tables can have different sort orders, but
+It comes as no surprise that two hash tables can have different sort orders, but
 this fact can also be used advantageously to sort the 'same items' in several
 ways. This is based on the ability to store a structure in several hash tables.