Only with corrective optics
Leica L sits 2.30mm further from the sensor than Fujifilm X. An adapter can only add distance, never remove it, so infinity focus is impossible without corrective glass in the adapter — which costs sharpness and usually a stop of light.
Coverage & framing. Fujifilm X lenses are built for a APS-C imaging circle, which is smaller than Full frame. Expect heavy vignetting or a forced crop on a Leica L body.