ftrace/x86: Adjust x86 regs.ip as like as x86-64

Adjust x86 regs.ip to ip + MCOUNT_INSN_SIZE as like as
on x86-64. This helps us to consolidate codes which use
regs->ip on both of x86/x86-64.

Link: http://lkml.kernel.org/r/20120905143100.10329.60109.stgit@localhost.localdomain

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

arch/x86/kernel/entry_32.S

@@ -1148,7 +1148,6 @@ ENTRY(ftrace_regs_caller)
 	 * ip location, and move flags into the return ip location.
 	 */
 	pushl 4(%esp)	/* save return ip into ip slot */
-	subl $MCOUNT_INSN_SIZE, (%esp)	/* Adjust ip */
 
 	pushl $0	/* Load 0 into orig_ax */
 	pushl %gs
@@ -1169,6 +1168,7 @@ ENTRY(ftrace_regs_caller)
 	movl $__KERNEL_CS,13*4(%esp)
 
 	movl 12*4(%esp), %eax	/* Load ip (1st parameter) */
+	subl $MCOUNT_INSN_SIZE, %eax	/* Adjust ip */
 	movl 0x4(%ebp), %edx	/* Load parent ip (2nd parameter) */
 	leal function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */
 	pushl %esp		/* Save pt_regs as 4th parameter */
@@ -1180,7 +1180,6 @@ GLOBAL(ftrace_regs_call)
 	movl 14*4(%esp), %eax	/* Move flags back into cs */
 	movl %eax, 13*4(%esp)	/* Needed to keep addl from modifying flags */
 	movl 12*4(%esp), %eax	/* Get return ip from regs->ip */
-	addl $MCOUNT_INSN_SIZE, %eax
 	movl %eax, 14*4(%esp)	/* Put return ip back for ret */
 
 	popl %ebx