awk: Remove last markings we have on awk

We normally don't add $FreeBSD$ to contrib software. However, these
changes date back to the CVS era of source code management and have been
overlooked. Now that all these files are back to the same as the
upstream bsd-features branch, remove the FreeBSD specific changes, which
are now just $FreeBSD$ and the (FreeBSD) in the version string.

MFC After:		2 weeks
Sponsored by:		Netflix

contrib/one-true-awk/b.c

@@ -24,9 +24,6 @@ THIS SOFTWARE.
 
 /* lasciate ogne speranza, voi ch'intrate. */
 
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
 #define	DEBUG
 
 #include <ctype.h>

contrib/one-true-awk/main.c

@@ -22,9 +22,7 @@ ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
 THIS SOFTWARE.
 ****************************************************************/
 
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-const char	*version = "version 20210215 (FreeBSD)";
+const char	*version = "version 20210215";
 
 #define DEBUG
 #include <stdio.h>

contrib/one-true-awk/run.c

@@ -22,9 +22,6 @@ ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
 THIS SOFTWARE.
 ****************************************************************/
 
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
 #define DEBUG
 #include <stdio.h>
 #include <ctype.h>