Improve a comment and fix some whitespace

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 59b2243..75f2256 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -2366,7 +2366,7 @@
      *     ECPoint      public;
      * } ServerECDHParams;
      *
-     *  1       curve_type (must be named curve)
+     *  1       curve_type (must be "named_curve")
      *  2..3    NamedCurve
      *  4       ECPoint.len
      *  5+      ECPoint contents