fixed syzkaller build via make clean delay

[whoismissing]

The latest version of syzkaller commit 0fbd49f48637cff2f7cf1ab0150e2c4ce8d97527 results in a Makefile error where the go version is detected and various imports are found to be undefined.

This error is present upon running the make clean in syzscope/scripts/deploy.sh

The error log appears as follows:

2023-05-11 13:50:23,726 [0] b'+ cd /home/user/SyzScope/work/incomplete/a8d38d1/gopath/src/github.com/google/syzkaller\n'
2023-05-11 13:50:23,726 [0] b'+ make clean\n'
2023-05-11 13:50:23,734 [0] b'Makefile:32: \x1b[31mrun command via tools/syz-env for best compatibility, see:\x1b(B\x1b[m\n'
2023-05-11 13:50:23,734 [0] b'Makefile:33: \x1b[31mhttps://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env\x1b(B\x1b[m\n'
2023-05-11 13:50:24,337 [0] b'# github.com/google/syzkaller/pkg/image\n'
2023-05-11 13:50:24,337 [0] b'pkg/image/compression.go:39:26: undefined: io.Discard\n'
2023-05-11 13:50:24,337 [0] b'pkg/image/compression.go:60:18: undefined: io.ReadAll\n'
2023-05-11 13:50:24,342 [0] b'note: module requires Go 1.19\n'
2023-05-11 13:50:24,538 [0] b'# golang.org/x/sys/unix\n'
2023-05-11 13:50:24,539 [0] b'vendor/golang.org/x/sys/unix/syscall.go:83:16: undefined: unsafe.Slice\n'
2023-05-11 13:50:24,539 [0] b'vendor/golang.org/x/sys/unix/syscall_linux.go:2271:9: undefined: unsafe.Slice\n'
2023-05-11 13:50:24,539 [0] b'vendor/golang.org/x/sys/unix/syscall_unix.go:118:7: undefined: unsafe.Slice\n'
2023-05-11 13:50:24,539 [0] b'vendor/golang.org/x/sys/unix/sysvshm_unix.go:33:7: undefined: unsafe.Slice\n'
2023-05-11 13:50:24,971 [0] b'Makefile:49: *** syz-make failed.  Stop.\n'

A simple fix I've found for this is to delay the make clean until after the target commit (in which custom syzkaller patches are applied) is checked out.

[plummm]

Cool, thanks.