ARM: kprobes: Move is_writeback define to header file.

This will be used later in other files.

Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>

arch/arm/kernel/kprobes-arm.c

@@ -69,12 +69,6 @@
 
 #define is_r15(insn, bitpos) (((insn) & (0xf << bitpos)) == (0xf << bitpos))
 
-/*
- * Test if load/store instructions writeback the address register.
- * if P (bit 24) == 0 or W (bit 21) == 1
- */
-#define is_writeback(insn) ((insn ^ 0x01000000) & 0x01200000)
-
 #define PSR_fs	(PSR_f|PSR_s)
 
 #define KPROBE_RETURN_INSTRUCTION	0xe1a0f00e	/* mov pc, lr */