more: fix file descriptor leak

When you view a file with the more command and run a shell, the file descriptor
for reading the file is leaked to that process.

To test, more any file. Then do !/bin/sh. At the prompt do "ls -l /proc/$$/fd"
and you'll see the leaked fd.

From: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>

text-utils/more.c

@@ -47,6 +47,7 @@
 #include <ctype.h>
 #include <signal.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <termios.h>
 #include <setjmp.h>
 #include <sys/ioctl.h>
@@ -478,6 +479,7 @@ checkf (fs, clearfirst)
 	}
 	if (magic(f, fs))
 		return((FILE *)NULL);
+	fcntl(fileno(f), F_SETFD, FD_CLOEXEC );
 	c = Getc(f);
 	*clearfirst = (c == '\f');
 	Ungetc (c, f);