posix: Consolidate Linux fsync syscall

posix: Consolidate Linux fsync syscall

This patch consolidates the fsync Linux syscall generation on
sysdeps/unix/sysv/linux/fsync.c.  It basically removes it from
architectures auto-generation list.

For arm it also removes the __errno_location call since fsync
is not called with SYSCALL_CANCEL with call arch-specific
INLINE_SYSCALL macro which in turn will call __set_errno macro
(and setting errno directly).

Checked on i686-linux-gnu, x86_64-linux-gnu, x86_64-linux-gnux32,
arch64-linux-gnu, arm-linux-gnueabihf, powerpc64le-linux-gnu,
sparc64-linux-gnu, and sparcv9-linux-gnu.

	* misc/Makefile (CFLAGS-fsync.c): New flag.
	* nptl/Makefile (CFLAGS-fsync.c): Likewise.
	* sysdeps/unix/syscalls.list (fsync): Remove from auto-generation
	syscall list.
	* sysdeps/unix/sysv/linux/fsync.c: New file.
	* sysdeps/unix/sysv/linux/arm/localplt.data [libpthread.so]
	(__errno_location): Remove.