ptrace: Remove duplicated include in ptrace.c

Fix following includecheck warning:
./arch/m68k/kernel/ptrace.c: linux/ptrace.h is included more than once.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Fixes: 153474b ("ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h")
Link: https://lkml.kernel.org/r/20220315235148.54253-1-yang.lee@linux.alibaba.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

Author: Yang Li

arch/m68k/kernel/ptrace.c

@@ -19,7 +19,6 @@
 #include <linux/ptrace.h>
 #include <linux/user.h>
 #include <linux/signal.h>
-#include <linux/ptrace.h>
 
 #include <linux/uaccess.h>
 #include <asm/page.h>