llvm: Fixed remaining warnings for llvm

This commit addresses warnings emitted from the llvm
compilers which were not encountered with gnu.

Signed-off-by: Noel Eck <noel.eck@intel.com>

src/pulsensor/pulsensor.hpp

@@ -104,7 +104,6 @@ private:
     uint8_t          is_pulse; /**< Is pulse check */
     uint8_t          first_beat; /**< First heartbeat */
     uint8_t          second_beat; /**< Second heartbeat */
-    uint8_t          pin; /**< Pin */
     uint8_t          ret; /**< Return value */
     mraa::Aio        pin_ctx; /**< The pin context */
 #if defined(SWIGJAVA) || defined(JAVACALLBACK)