Input: synaptics-rmi4 - introduce rmi_f34v7_check_command_status() helper

Input: synaptics-rmi4 - introduce rmi_f34v7_check_command_status() helper

Add a function that waits for the last command to complete and checks
the status, and use it where appropriate. This prepares for the subsequent
fix of the completion condition in rmi_f34_attention(), which would
previously lead to a timeout instead of a more detailed error message
whenever a command was unsuccessful with v7/v8 bootloaders.

Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20220608124808.51402-3-matthias.schiffer@ew.tq-group.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>