Fix typos prior to release

Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
diff --git a/programs/psa/hmac_demo.c b/programs/psa/hmac_demo.c
index 6238892..f949a89 100644
--- a/programs/psa/hmac_demo.c
+++ b/programs/psa/hmac_demo.c
@@ -81,7 +81,7 @@
 
 /* Run a PSA function and bail out if it fails.
  * The symbolic name of the error code can be recovered using:
- * programs/psa/psa_consant_name status <value> */
+ * programs/psa/psa_constant_name status <value> */
 #define PSA_CHECK( expr )                                       \
     do                                                          \
     {                                                           \