Make ppc64 __FD_ISSET() return a proper boolean return value.

(The broken macro only triggers for non-gcc compiles, but
still..)

include/asm-ppc64/posix_types.h

@@ -48,7 +48,7 @@ typedef struct {
 
 #define	__FD_SET(d, set)	((set)->fds_bits[__FDELT(d)] |= __FDMASK(d))
 #define	__FD_CLR(d, set)	((set)->fds_bits[__FDELT(d)] &= ~__FDMASK(d))
-#define	__FD_ISSET(d, set)	((set)->fds_bits[__FDELT(d)] & __FDMASK(d))
+#define	__FD_ISSET(d, set)	(((set)->fds_bits[__FDELT(d)] & __FDMASK(d)) != 0)
 #define	__FD_ZERO(set)	\
   ((void) memset ((__ptr_t) (set), 0, sizeof (__kernel_fd_set)))