powerpc/ppc64: Remove the unneeded load of ti_flags in resume_kernel

We already got the value of current_thread_info and ti_flags and store
them into r9 and r4 respectively before jumping to resume_kernel. So
there is no reason to reload them again.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/entry_64.S

@@ -673,9 +673,7 @@ _GLOBAL(ret_from_except_lite)
 
 resume_kernel:
 	/* check current_thread_info, _TIF_EMULATE_STACK_STORE */
-	CURRENT_THREAD_INFO(r9, r1)
-	ld	r8,TI_FLAGS(r9)
-	andis.	r8,r8,_TIF_EMULATE_STACK_STORE@h
+	andis.	r8,r4,_TIF_EMULATE_STACK_STORE@h
 	beq+	1f
 
 	addi	r8,r1,INT_FRAME_SIZE	/* Get the kprobed function entry */