Tidy-up comment

Co-authored-by: Tom Cosgrove <tom.cosgrove@arm.com>
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/platform_util.c b/library/platform_util.c
index 60b77e8..35e29ae 100644
--- a/library/platform_util.c
+++ b/library/platform_util.c
@@ -76,7 +76,7 @@
  * (refer to http://www.daemonology.net/blog/2014-09-05-erratum.html for
  * details), optimizations of the following form are still possible:
  *
- * if(memset_func != memset)
+ * if (memset_func != memset)
  *     memset_func(buf, 0, len);
  *
  * Note that it is extremely difficult to guarantee that