generic/019: fix incorrect unset statements

Fix incorrect usage of unset -- one passes the name of the variable, not
the *value* contained within it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>
1 file changed