common/fdlimit: fix windows build (#19068)

(cherry picked from commit ba90a4aaa4)

common/fdlimit/fdlimit_windows.go

@@ -16,7 +16,9 @@
 
 package fdlimit
 
-import "errors"
+import "fmt"
+
+const hardlimit = 16384
 
 // Raise tries to maximize the file descriptor allowance of this process
 // to the maximum hard-limit allowed by the OS.
@@ -27,8 +29,8 @@ func Raise(max uint64) (uint64, error) {
 	//    changeable from within a running process
 	// This way we can always "request" raising the limits, which will either have
 	// or not have effect based on the platform we're running on.
-	if max > 16384 {
-		return errors.New("file descriptor limit (16384) reached")
+	if max > hardlimit {
+		return hardlimit, fmt.Errorf("file descriptor limit (%d) reached", hardlimit)
 	}
 	return max, nil
 }
@@ -37,7 +39,7 @@ func Raise(max uint64) (uint64, error) {
 // process.
 func Current() (int, error) {
 	// Please see Raise for the reason why we use hard coded 16K as the limit
-	return 16384, nil
+	return hardlimit, nil
 }
 
 // Maximum retrieves the maximum number of file descriptors this process is