MF Symlinks are regular files containing content in a specified format.

The function couldbe_mf_symlink() checks the mode for a set S_IFREG bit
as a test to confirm that it is a regular file. This bit is also set for
other filetypes and simply checking for this bit being set may return
false positives.

We ensure that we are actually checking for a regular file by using the
S_ISREG macro to test instead.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Reported-by: NNeil Brown <neilb@suse.de>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NSteve French <smfrench@gmail.com>