Fix float128_private.h redefinition of SET_RESTORE_ROUNDL.

Fix float128_private.h redefinition of SET_RESTORE_ROUNDL.

As with other long double identifiers, float128_private.h has a
redefinition of SET_RESTORE_ROUNDL.  However, that redefinition is
broken, since this is a macro with one argument being defined to take
no arguments.  This patch fixes the redefinition.  (x86_64 needs the
redefinition because SET_RESTORE_ROUNDL only changes the x87 rounding
mode, whereas _Float128 arithmetic uses the SSE rounding mode instead
on x86_64.)

Tested for x86_64 (in conjunction with float128 patches).

	* sysdeps/ieee754/float128/float128_private.h
	[SET_RESTORE_ROUNDF128] (SET_RESTORE_ROUNDL): Take an argument and
	pass it to SET_RESTORE_ROUNDF128.