sbin/hammer: Remove redundant ioctl(GET_PSEUDOFS) call in getpfs()

sbin/hammer: Remove redundant ioctl(GET_PSEUDOFS) call in getpfs()

If scanpfsid() failed, it needs to try to open(2) the path whether
it's a symlink or a file or a directory, but it needs not to call
ioctl(GET_PSEUDOFS) which gets called right after this anyway.

The error message "Cannot access PFS" is misleading too, because
once scanpfsid() fails, the path isn't necessarily a PFS or a symlink
to a PFS.

Also note that calling this ioctl with -1 set to pfs.pfs_id is okay.
In that case, the ioctl will try to detect the PFS id based on fd.