[fusl] Remove socketcall abstraction

fusl/src/network/recvmsg.c

 #include <sys/socket.h>
 #include <limits.h>
 #include "syscall.h"
 #include "libc.h"
 
 ssize_t recvmsg(int fd, struct msghdr* msg, int flags) {
   ssize_t r;
 #if LONG_MAX > INT_MAX
   struct msghdr h, *orig = msg;
   if (msg) {
     h = *msg;
     h.__pad1 = h.__pad2 = 0;
     msg = &h;
   }
 #endif
-  r = socketcall_cp(recvmsg, fd, msg, flags, 0, 0, 0);
+  r = syscall_cp(SYS_recvmsg, fd, msg, flags, 0, 0, 0);
 #if LONG_MAX > INT_MAX
   if (orig)
     *orig = h;
 #endif
   return r;
 }