x86: map vsyscalls early enough

map vsyscalls early enough. This is important if a __vsyscall_fn
function is used by other kernel code too.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/setup_64.c

@@ -45,6 +45,7 @@
 #include <asm/mtrr.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
+#include <asm/vsyscall.h>
 #include <asm/io.h>
 #include <asm/smp.h>
 #include <asm/msr.h>
@@ -453,6 +454,7 @@ void __init setup_arch(char **cmdline_p)
 #endif
 	reserve_crashkernel();
 	paging_init();
+	map_vsyscall();
 
 	early_quirks();