[ARM] Remove RETINSTR macro

RETINSTR is a left-over from the days when we had 26-bit and
32-bit CPU support integrated into the same tree.  Since this
is no longer the case, we can now remove RETINSTR.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/entry-common.S

@@ -340,7 +340,7 @@ sys_mmap2:
 		streq	r5, [sp, #4]
 		beq	do_mmap2
 		mov	r0, #-EINVAL
-		RETINSTR(mov,pc, lr)
+		mov	pc, lr
 #else
 		str	r5, [sp, #4]
 		b	do_mmap2