[MINOR] changed fd_set*/fd_clr* functions to return ints

The fd_* functions now return ints so that they can be
factored when appropriate.
diff --git a/src/ev_epoll.c b/src/ev_epoll.c
index 65b3d74..56049bc 100644
--- a/src/ev_epoll.c
+++ b/src/ev_epoll.c
@@ -47,22 +47,24 @@
  * instead of the usual macros improve the FD_* performance by about 80%,
  * and that marking them regparm(2) adds another 20%.
  */
-REGPRM2 static int __fd_isset(const int fd, const int dir)
+REGPRM2 static int __fd_isset(const int fd, int dir)
 {
 	return FD_ISSET(fd, fd_evts[dir]);
 }
 
-REGPRM2 static void __fd_set(const int fd, const int dir)
+REGPRM2 static int __fd_set(const int fd, int dir)
 {
 	FD_SET(fd, fd_evts[dir]);
+	return 0;
 }
 
-REGPRM2 static void __fd_clr(const int fd, const int dir)
+REGPRM2 static int __fd_clr(const int fd, int dir)
 {
 	FD_CLR(fd, fd_evts[dir]);
+	return 0;
 }
 
-REGPRM2 static int __fd_cond_s(const int fd, const int dir)
+REGPRM2 static int __fd_cond_s(const int fd, int dir)
 {
 	int ret;
 	ret = !FD_ISSET(fd, fd_evts[dir]);
@@ -71,7 +73,7 @@
 	return ret;
 }
 
-REGPRM2 static int __fd_cond_c(const int fd, const int dir)
+REGPRM2 static int __fd_cond_c(const int fd, int dir)
 {
 	int ret;
 	ret = FD_ISSET(fd, fd_evts[dir]);
diff --git a/src/ev_poll.c b/src/ev_poll.c
index d43fa0c..542742a 100644
--- a/src/ev_poll.c
+++ b/src/ev_poll.c
@@ -37,22 +37,24 @@
  * instead of the usual macros improve the FD_* performance by about 80%,
  * and that marking them regparm(2) adds another 20%.
  */
-REGPRM2 static int __fd_isset(const int fd, const int dir)
+REGPRM2 static int __fd_isset(const int fd, int dir)
 {
 	return FD_ISSET(fd, fd_evts[dir]);
 }
 
-REGPRM2 static void __fd_set(const int fd, const int dir)
+REGPRM2 static int __fd_set(const int fd, int dir)
 {
 	FD_SET(fd, fd_evts[dir]);
+	return 0;
 }
 
-REGPRM2 static void __fd_clr(const int fd, const int dir)
+REGPRM2 static int __fd_clr(const int fd, int dir)
 {
 	FD_CLR(fd, fd_evts[dir]);
+	return 0;
 }
 
-REGPRM2 static int __fd_cond_s(const int fd, const int dir)
+REGPRM2 static int __fd_cond_s(const int fd, int dir)
 {
 	int ret;
 	ret = !FD_ISSET(fd, fd_evts[dir]);
@@ -61,7 +63,7 @@
 	return ret;
 }
 
-REGPRM2 static int __fd_cond_c(const int fd, const int dir)
+REGPRM2 static int __fd_cond_c(const int fd, int dir)
 {
 	int ret;
 	ret = FD_ISSET(fd, fd_evts[dir]);
diff --git a/src/ev_select.c b/src/ev_select.c
index 1ab7119..d019c21 100644
--- a/src/ev_select.c
+++ b/src/ev_select.c
@@ -35,22 +35,24 @@
  * instead of the usual macros improve the FD_* performance by about 80%,
  * and that marking them regparm(2) adds another 20%.
  */
-REGPRM2 static int __fd_isset(const int fd, const int dir)
+REGPRM2 static int __fd_isset(const int fd, int dir)
 {
 	return FD_ISSET(fd, fd_evts[dir]);
 }
 
-REGPRM2 static void __fd_set(const int fd, const int dir)
+REGPRM2 static int __fd_set(const int fd, int dir)
 {
 	FD_SET(fd, fd_evts[dir]);
+	return 0;
 }
 
-REGPRM2 static void __fd_clr(const int fd, const int dir)
+REGPRM2 static int __fd_clr(const int fd, int dir)
 {
 	FD_CLR(fd, fd_evts[dir]);
+	return 0;
 }
 
-REGPRM2 static int __fd_cond_s(const int fd, const int dir)
+REGPRM2 static int __fd_cond_s(const int fd, int dir)
 {
 	int ret;
 	ret = !FD_ISSET(fd, fd_evts[dir]);
@@ -59,7 +61,7 @@
 	return ret;
 }
 
-REGPRM2 static int __fd_cond_c(const int fd, const int dir)
+REGPRM2 static int __fd_cond_c(const int fd, int dir)
 {
 	int ret;
 	ret = FD_ISSET(fd, fd_evts[dir]);
@@ -68,7 +70,7 @@
 	return ret;
 }
 
-REGPRM1 static void __fd_rem(const int fd)
+REGPRM1 static void __fd_rem(int fd)
 {
 	FD_CLR(fd, fd_evts[DIR_RD]);
 	FD_CLR(fd, fd_evts[DIR_WR]);