libsmack: fix memory leak

Signed-off-by: Zbigniew Jasinski <z.jasinski@samsung.com>
Revert "libsmack: Terminate attribute string"

This reverts commit cbdd52af82bce9d2ab79e43e0757c4d077d08907.
Merge remote-tracking branch 'penszo/v1.0.x' into v1.0.x