media: camera-sensor.rst: fix a doc build warning

	Documentation/driver-api/media/camera-sensor.rst:123: WARNING: Inline literal start-string without end-string.

There's a missing blank space over there.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/driver-api/media/camera-sensor.rst

@@ -123,7 +123,7 @@ Control framework
 ``v4l2_ctrl_handler_setup()`` function may not be used in the device's runtime
 PM ``runtime_resume`` callback, as it has no way to figure out the power state
 of the device. This is because the power state of the device is only changed
-after the power state transition has taken place. The ``s_ctrl``callback can be
+after the power state transition has taken place. The ``s_ctrl`` callback can be
 used to obtain device's power state after the power state transition:
 
 .. c:function::