smbd: remove coupling between get_ea_names_from_file() and "ea support"

smbd: remove coupling between get_ea_names_from_file() and "ea support"

The "ea support" configuration variable determines whether smbd
should attempt to manipulate extended attributes via SMB protocol.
It does not pertain to the underlying storage and its support for
extended attributes.

get_ea_names_from_file() is being used also by vfs_streams_xattr -
a module which has nothing to do with client-visible extended
attributes. As such, vfs_streams_xattr should be able to operate
irrespective of the value of "ea support".

This patch moves the check for ea support to the callers.

Signed-off-by: Uri Simchoni <uri@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>