Remove unneeded NULL pointer checks in LMS tests

Signed-off-by: Raef Coles <raef.coles@arm.com>
diff --git a/tests/suites/test_suite_lmots.function b/tests/suites/test_suite_lmots.function
index f2ce29a..0f33925 100644
--- a/tests/suites/test_suite_lmots.function
+++ b/tests/suites/test_suite_lmots.function
@@ -136,8 +136,7 @@
     }
 
 exit:
-    if( tmp_sig != NULL )
-        mbedtls_free( tmp_sig );
+    mbedtls_free( tmp_sig );
     mbedtls_lmots_public_free( &ctx );
 }
 /* END_CASE */
diff --git a/tests/suites/test_suite_lms.function b/tests/suites/test_suite_lms.function
index dd37f31..ff117ea 100644
--- a/tests/suites/test_suite_lms.function
+++ b/tests/suites/test_suite_lms.function
@@ -138,8 +138,7 @@
     }
 
 exit:
-    if( tmp_sig != NULL )
-        mbedtls_free( tmp_sig );
+    mbedtls_free( tmp_sig );
     mbedtls_lms_public_free( &ctx );
 }
 /* END_CASE */
@@ -192,8 +191,7 @@
     }
 
 exit:
-    if( exported_pub_key != NULL )
-        mbedtls_free( exported_pub_key );
+    mbedtls_free( exported_pub_key );
     mbedtls_lms_public_free( &ctx );
 }
 /* END_CASE */