libgcc/config/arm/linux-atomic-64bit.c uses __write to print an error
message if the 64bit cmpxchg method is not available in the kernel.

__write is not part of the public libc abi, so use write instead.
(user code may define write in iso c conforming mode and then the
error message may not be visible before the crash.)

The return type in the declaration of write is fixed too.

OK for trunk and backporting?

libgcc/ChangeLog:

2015-11-06  Szabolcs Nagy  <szabolcs.nagy@arm.com>

	PR target/68059
	* config/arm/linux-atomic-64bit.c (__write): Rename to...
	(write): ...this and fix the return type.