Input: ims-pcu - return error code rather than -ENOMEM

Input: ims-pcu - return error code rather than -ENOMEM

Currently the assignment of -ENOMEM to error is redundant because error
is not being read and -ENOMEM is being hard coded as an error return.
Fix this by returning the error code in variable 'error'; this also
allows the error code from a failed call to input_register_device to
be preserved and returned to the caller rather than just returning
a possibly inappropriate -ENOMEM.

Kudos to Dan Carpenter for the suggestion of an improved fix.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200603152151.139337-1-colin.king@canonical.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>