fsck: '#' is only a comment character at the beginning of an fstab line

fsck: '#' is only a comment character at the beginning of an fstab line

Fuse and ssh fstab lines such as:

  wdfs#https://dav.hoster.com/foo/bar /mnt/hoster fuse user,noauto 0 0

will cause fsck to issue warnings about invalid fstab lines, because
fsck was previously treating '#' as a comment when it appeared
anywhere in an fstab line, not just at the beginning of the line.

Addresses-Gentoo-bug: #195405
Addresses-Sourceforge-bug: #1826147

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>