Add missing boot.4th verification

During initialization of the forth interpreter
the loader looks for "/boot/boot.4th"
and executes any code found there.
That file was loaded bypassing verification.
Add a call to verify_file to change that.

Submitted by: Kornel Duleba <mindal@semihalf.com>
Reviewed by: sjg
Obtained from: Semihalf
Sponsored by: Stormshield

stand/common/interp_forth.c

@@ -283,6 +283,12 @@ bf_init(void)
 
 	/* try to load and run init file if present */
 	if ((fd = open("/boot/boot.4th", O_RDONLY)) != -1) {
+#ifdef LOADER_VERIEXEC
+		if (verify_file(fd, "/boot/boot.4th", 0, VE_GUESS) < 0) {
+			close(fd);
+			return;
+		}
+#endif
 		(void)ficlExecFD(bf_vm, fd);
 		close(fd);
 	}