cmd: use slices.Equal to simplify code

#57433 added slices.Equal, using it can reduce the amount of code

Change-Id: I70d14b6c4c24da641a34ed36c900d9291033f526
Reviewed-on: https://go-review.googlesource.com/c/go/+/492576
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: shuang cui <imcusg@gmail.com>

src/cmd/covdata/argsmerge.go

@@ -6,6 +6,7 @@ package main
 
 import (
  "fmt"
+ "slices"
  "strconv"
 )
 
@@ -20,25 +21,13 @@ type argstate struct {
  initialized bool
 }
 
-func ssleq(s1 []string, s2 []string) bool {
- if len(s1) != len(s2) {
- return false
- }
- for i := range s1 {
- if s1[i] != s2[i] {
- return false
- }
- }
- return true
-}
-
 func (a *argstate) Merge(state argvalues) {
  if !a.initialized {
  a.state = state
  a.initialized = true
  return
  }
- if !ssleq(a.state.osargs, state.osargs) {
+ if !slices.Equal(a.state.osargs, state.osargs) {
  a.state.osargs = nil
  }
  if state.goos != a.state.goos {