firmware_loader: Check fw_state_is_done in loading_store

Rename fw_sysfs_done() and fw_sysfs_loading() to fw_state_is_done() and
fw_state_is_loading() respectively, and place them along side companion
functions in drivers/base/firmware_loader/firmware.h.

Use the fw_state_is_done() function to exit early from
firmware_loading_store() if the state is already "done". This is being done
in preparation for supporting persistent sysfs nodes to allow userspace to
upload firmware to a device, potentially reusing the sysfs loading and data
files multiple times.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Tianfei zhang <tianfei.zhang@intel.com>
Tested-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Link: https://lore.kernel.org/r/20220421212204.36052-3-russell.h.weight@intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>