cmd/internal/obj/arm64: remove bogus omovlit return value check

omovlit never returns zero, so it does not make any sense to check for that.
Additionally, no other call site does this.

Change-Id: I5769dcdb557bed4ec4d727abe0869a1549fcf04c
Reviewed-on: https://go-review.googlesource.com/c/go/+/461136
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Eric Fang <eric.fang@arm.com>
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Gopher Robot <gobot@golang.org>

src/cmd/internal/obj/arm64/asm7.go

@@ -3997,10 +3997,6 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 
 	case 34: /* mov $lacon,R */
 		o1 = c.omovlit(AMOVD, p, &p.From, REGTMP)
-
-		if o1 == 0 {
-			break
-		}
 		o2 = c.opxrrr(p, AADD, false)
 		o2 |= REGTMP & 31 << 16
 		o2 |= LSL0_64