testsuite: arm: Use correct the expected asm in epilog-1.c test

In r14.2.0-376-g724446556e5, I accidentally introduced a regression in
the expected assembler as the csinc instruction was not used for
armv8.1-m.main.

The generated assembler for armv8.1-m.main is:
        push    {r3, r4, r5, lr}
        ldr     r4, .L5
        ldr     r5, [r4]
        adds    r4, r2, #1
        tst     r5, #4
        it      ne
        movne   r2, r4
        bl      bar
        movs    r0, #0
        pop     {r3, r4, r5, pc}

gcc/testsuite/ChangeLog:

	* gcc.target/arm/epilog-1.c: Corrected armv8.1.m-main asm.

Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>

gcc/testsuite/gcc.target/arm/epilog-1.c

@@ -20,8 +20,10 @@ Below block is for non-armv8.1-m.main
 ** |
 
 Below block is for armv8.1-m.main
+**	adds	(r[0-9]+), r2, #1
 **	tst	r[0-9]+, #4
-**	csinc	r2, r2, r2, eq
+**	it	ne
+**	movne	r2, \1
 
 ** )
 **	bl	bar