staging: rtl8723bs: Fix two possible sleep-in-atomic-context bugs in translate_scan()

staging: rtl8723bs: Fix two possible sleep-in-atomic-context bugs in translate_scan()

The driver may sleep with holding a spinlock.
The function call paths (from bottom to top) in Linux-4.16.7 are:

[FUNC] kzalloc(GFP_KERNEL)
drivers/staging/rtl8723bs/os_dep/ioctl_linux.c, 323:
		kzalloc in translate_scan
drivers/staging/rtl8723bs/os_dep/ioctl_linux.c, 1554:
		translate_scan in rtw_wx_get_scan
drivers/staging/rtl8723bs/os_dep/ioctl_linux.c, 1533:
		spin_lock_bh in rtw_wx_get_scan

[FUNC] kzalloc(GFP_KERNEL)
drivers/staging/rtl8723bs/os_dep/ioctl_linux.c, 455:
		kzalloc in translate_scan
drivers/staging/rtl8723bs/os_dep/ioctl_linux.c, 1554:
		translate_scan in rtw_wx_get_scan
drivers/staging/rtl8723bs/os_dep/ioctl_linux.c, 1533:
		spin_lock_bh in rtw_wx_get_scan

To fix these bugs, GFP_KERNEL is replaced with GFP_ATOMIC.

These bugs are found by my static analysis tool (DSAC-2) and checked by
my code review.

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