xirc2ps_cs: remove redundant assignment to variable okay, clean up freespace

xirc2ps_cs: remove redundant assignment to variable okay, clean up freespace

The variable okay is being initialized with a value that is never
read, it is being re-assigned later on. The initialization is
redundant and can be removed.  Also clean up assignment to
variable freespace using an assignment and mask operation.

Cleans up clang scan build warning:
drivers/net/ethernet/xircom/xirc2ps_cs.c:1244:5: warning: Value stored
to 'okay' is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240205213643.1850420-1-colin.i.king@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>