invoke.texi: Correct -Wformat-overflow code sample.

gcc/ChangeLog:

2018-02-14  Indu Bhagat  <indu.bhagat@oracle.com>

	* doc/invoke.texi: Correct -Wformat-overflow code sample.

From-SVN: r257680

gcc/ChangeLog

+2018-02-14  Indu Bhagat  <indu.bhagat@oracle.com>
+
+	* doc/invoke.texi: Correct -Wformat-overflow code sample.
+
 2018-02-14  Martin Sebor  <msebor@redhat.com>
 
 	PR tree-optimization/83698

gcc/doc/invoke.texi

@@ -4184,7 +4184,7 @@ warning, though it may not be sufficient to avoid the overflow.
 @smallexample
 void f (int a, int b)
 @{
-  char buf [12];
+  char buf [13];
   sprintf (buf, "a = %i, b = %i\n", a, b);
 @}
 @end smallexample