Fix typos prior to release

Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
diff --git a/programs/test/benchmark.c b/programs/test/benchmark.c
index ecb093e..6313c52 100644
--- a/programs/test/benchmark.c
+++ b/programs/test/benchmark.c
@@ -416,7 +416,7 @@
     Sleep( alarmMs );
     mbedtls_timing_alarmed = 1;
     /* _endthread will be called implicitly on return
-     * That ensures execution of thread funcition's epilogue */
+     * That ensures execution of thread function's epilogue */
 }
 
 static void mbedtls_set_alarm( int seconds )