ftrace: copy + paste typo in asm/ftrace.h

Signed-off-by: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <srostedt@redhat.co>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/asm-x86/ftrace.h

 #ifndef _ASM_X86_FTRACE
-#define _ASM_SPARC64_FTRACE
+#define _ASM_X86_FTRACE
 
 #ifdef CONFIG_FTRACE
 #define MCOUNT_ADDR		((long)(mcount))