unix: drop fallback to inotifyInit in InotifyInit on linux/amd64

The minimum required Linux kernel version for Go 1.18 will be changed to
2.6.32, see golang/go#45964. The current minimum required version is
2.6.23 and the inotify_init1 syscall was added in 2.6.27, so the
fallback to inotifyInit and inotifyInit itself can be removed on
linux/amd64.

For golang/go#45964

Change-Id: I8dc83ef04d74cfc9ec80da503076b9acfa9c365a
Reviewed-on: https://go-review.googlesource.com/c/sys/+/347330
Trust: Tobias Klauser <[email protected]>
Run-TryBot: Tobias Klauser <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Matt Layher <[email protected]>

Author: tklauser

unix/syscall_linux_amd64.go

@@ -21,15 +21,9 @@ package unix
 //sysnb	Getgid() (gid int)
 //sysnb	Getrlimit(resource int, rlim *Rlimit) (err error)
 //sysnb	Getuid() (uid int)
-//sysnb	inotifyInit() (fd int, err error)
 
 func InotifyInit() (fd int, err error) {
-	// First try inotify_init1, because Android's seccomp policy blocks the latter.
-	fd, err = InotifyInit1(0)
-	if err == ENOSYS {
-		fd, err = inotifyInit()
-	}
-	return
+	return InotifyInit1(0)
 }
 
 //sys	Ioperm(from int, num int, on int) (err error)