[ARM] 4665/1: fix __und_usr wrt accessing the undefined insn in user space

The ldrt fixup code expects r9 to be set.
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/entry-armv.S

@@ -453,9 +453,9 @@ __und_usr:
 	@
 	@  r0 - instruction
 	@
-1:	ldrt	r0, [r4]
 	adr	r9, ret_from_exception
 	adr	lr, __und_usr_unknown
+1:	ldrt	r0, [r4]
 	@
 	@ fallthrough to call_fpe
 	@