cmd/go/internal: optimize code with newly defined time.DateTime constants

Signed-off-by: cui fliter <[email protected]>

Author: cuishuang

src/cmd/go/internal/modfetch/codehost/vcs.go

@@ -587,7 +587,7 @@ func fossilParseStat(rev, out string) (*RevInfo, error) {
 			if len(f) != 5 || len(f[1]) != 40 || f[4] != "UTC" {
 				return nil, vcsErrorf("unexpected response from fossil info: %q", line)
 			}
-			t, err := time.Parse("2006-01-02 15:04:05", f[2]+" "+f[3])
+			t, err := time.Parse(time.DateTime, f[2]+" "+f[3])
 			if err != nil {
 				return nil, vcsErrorf("unexpected response from fossil info: %q", line)
 			}

src/cmd/go/internal/vcs/vcs.go

@@ -561,7 +561,7 @@ func fossilStatus(vcsFossil *Cmd, rootDir string) (Status, error) {
 	}
 	rev := checkout[:i]
 
-	commitTime, err := time.ParseInLocation("2006-01-02 15:04:05", checkout[i+1:], time.UTC)
+	commitTime, err := time.ParseInLocation(time.DateTime, checkout[i+1:], time.UTC)
 	if err != nil {
 		return Status{}, fmt.Errorf("%v: %v", errFossilInfo, err)
 	}