Fix improper spacing

Spacing between brackets did not follow the appropriate coding style

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
diff --git a/tests/suites/test_suite_aes.function b/tests/suites/test_suite_aes.function
index dac6edc..1892c25 100644
--- a/tests/suites/test_suite_aes.function
+++ b/tests/suites/test_suite_aes.function
@@ -208,7 +208,7 @@
 
     TEST_ASSERT( mbedtls_aes_crypt_xts( &ctx, MBEDTLS_AES_ENCRYPT, length, data_unit, src, output ) == retval );
 exit:
-    mbedtls_aes_xts_free(&ctx);
+    mbedtls_aes_xts_free( &ctx );
 }
 /* END_CASE */