Fix compiler errors on many platforms.

Also added comment to explain why I added a seemingly pointless goto

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 5c5c457..fa5556e 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -3636,9 +3636,10 @@
         }
     }
 
-    goto exit;
 
-exit:
+    /* Goto is required to silence warnings about unused labels, as we
+     * don't actually do any test assertions in this function. */
+    goto exit;
 }
 /* END_CASE */
 
@@ -3688,9 +3689,9 @@
         }
     }
 
+    /* Goto is required to silence warnings about unused labels, as we
+     * don't actually do any test assertions in this function. */
     goto exit;
-
-exit:
 }
 /* END_CASE */