kexec-tools,kexec: Fix build with latest klibc

klibc has changed its signature of reboot() API
adapt the use here

Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-initramfs/recipes-kernel/kexec/kexec-tools-klibc/klibc-reboot.patch

@@ -0,0 +1,11 @@
+--- a/kexec/kexec.c
++++ b/kexec/kexec.c
+@@ -901,7 +901,7 @@ static int my_exec(void)
+ 	if (xen_present())
+ 		xen_kexec_exec();
+ 	else
+-		reboot(LINUX_REBOOT_CMD_KEXEC);
++		reboot(LINUX_REBOOT_CMD_KEXEC, NULL);
+ 	/* I have failed if I make it here */
+ 	fprintf(stderr, "kexec failed: %s\n", 
+ 		strerror(errno));