tty: ipwireless: Replace GFP_ATOMIC with GFP_KERNEL in ipwireless_network_create

tty: ipwireless: Replace GFP_ATOMIC with GFP_KERNEL in ipwireless_network_create

ipwireless_network_create() is never called in atomic context.

The call chain ending up at ipwireless_network_create() is:
[1] ipwireless_network_create() <- config_ipwireless() <-
	ipwireless_attach()
ipwireless_attach() is only set as ".probe" in struct pcmcia_driver.

Despite never getting called from atomic context,
ipwireless_network_create() calls kzalloc() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>