virtiofs: clean up error handling in virtio_fs_get_tree()

stable inclusion
from stable-v5.10.179
commit cf08dc79168a80a7cf4dad14a3cc0f2f87561d11
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8C809

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cf08dc79168a80a7cf4dad14a3cc0f2f87561d11



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commit 833c5a42 upstream.

Avoid duplicating error cleanup.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Yang Bo <yb203166@antfin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>