Fix typos prior to release

Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
diff --git a/library/pkcs7.c b/library/pkcs7.c
index e4238b6..5b22afa 100644
--- a/library/pkcs7.c
+++ b/library/pkcs7.c
@@ -314,7 +314,7 @@
     if( ret != 0 )
         goto out;
 
-    /* Asssume authenticatedAttributes is nonexistent */
+    /* Assume authenticatedAttributes is nonexistent */
 
     ret = pkcs7_get_digest_algorithm( p, end_signer, &signer->sig_alg_identifier );
     if( ret != 0 )