gdb/NEWS: minor white space fix

Spotted a small white space mistake in the NEWS file.  Fixed.
diff --git a/gdb/NEWS b/gdb/NEWS
index a2ebf12..2e48a00 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -46,7 +46,7 @@
   In systems that don't support linkage namespaces, these always return 1
   and [[0]] respectively.
 
- * Add record full support for rv64gc architectures
+* Add record full support for rv64gc architectures
 
 * New commands