Make eventfd argument names match OS docs/headers

(backport <#4830>)
(cherry picked from commit 3ff2a88)

Author: krobelus

src/fuchsia/mod.rs

@@ -3873,7 +3873,7 @@ extern "C" {
         len: size_t,
         flags: c_uint,
     ) -> ssize_t;
-    pub fn eventfd(init: c_uint, flags: c_int) -> c_int;
+    pub fn eventfd(initval: c_uint, flags: c_int) -> c_int;
     pub fn sched_rr_get_interval(pid: crate::pid_t, tp: *mut crate::timespec) -> c_int;
     pub fn sem_timedwait(sem: *mut sem_t, abstime: *const crate::timespec) -> c_int;
     pub fn sem_getvalue(sem: *mut sem_t, sval: *mut c_int) -> c_int;

src/unix/bsd/freebsdlike/freebsd/mod.rs

@@ -4795,7 +4795,7 @@ extern "C" {
     pub fn memfd_create(name: *const c_char, flags: c_uint) -> c_int;
     pub fn setaudit(auditinfo: *const auditinfo_t) -> c_int;
 
-    pub fn eventfd(init: c_uint, flags: c_int) -> c_int;
+    pub fn eventfd(initval: c_uint, flags: c_int) -> c_int;
     pub fn eventfd_read(fd: c_int, value: *mut eventfd_t) -> c_int;
     pub fn eventfd_write(fd: c_int, value: eventfd_t) -> c_int;
 

src/unix/linux_like/android/mod.rs

@@ -3560,7 +3560,7 @@ extern "C" {
         len: size_t,
         flags: c_uint,
     ) -> ssize_t;
-    pub fn eventfd(init: c_uint, flags: c_int) -> c_int;
+    pub fn eventfd(initval: c_uint, flags: c_int) -> c_int;
     pub fn eventfd_read(fd: c_int, value: *mut eventfd_t) -> c_int;
     pub fn eventfd_write(fd: c_int, value: eventfd_t) -> c_int;
     pub fn sched_rr_get_interval(pid: crate::pid_t, tp: *mut crate::timespec) -> c_int;

src/unix/linux_like/linux/mod.rs

@@ -6094,7 +6094,7 @@ extern "C" {
         len: size_t,
         flags: c_uint,
     ) -> ssize_t;
-    pub fn eventfd(init: c_uint, flags: c_int) -> c_int;
+    pub fn eventfd(initval: c_uint, flags: c_int) -> c_int;
     pub fn eventfd_read(fd: c_int, value: *mut eventfd_t) -> c_int;
     pub fn eventfd_write(fd: c_int, value: eventfd_t) -> c_int;
 

src/unix/solarish/illumos.rs

@@ -212,7 +212,7 @@ pub const TFD_TIMER_ABSTIME: i32 = 1 << 0;
 pub const TFD_TIMER_CANCEL_ON_SET: i32 = 1 << 1;
 
 extern "C" {
-    pub fn eventfd(init: c_uint, flags: c_int) -> c_int;
+    pub fn eventfd(initval: c_uint, flags: c_int) -> c_int;
 
     pub fn epoll_pwait(
         epfd: c_int,