x86: make early_console static in early_printk.c

Not necessary to expose it, also fixes sparse warning.

arch/x86/kernel/early_printk.c:196:16: warning: symbol 'early_console' was not declared. Should it be static?
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/early_printk.c

@@ -193,7 +193,7 @@ static struct console simnow_console = {
 };
 
 /* Direct interface for emergencies */
-struct console *early_console = &early_vga_console;
+static struct console *early_console = &early_vga_console;
 static int early_console_initialized = 0;
 
 void early_printk(const char *fmt, ...)