Replaced Linux syscall macros by libc macros.

User-space programs should use the SYS_*form, as documented in
syscall(2).  That also adds compatibility to non-Linux systems.

src/nxt_clone.c

@@ -14,9 +14,9 @@ pid_t
 nxt_clone(nxt_int_t flags)
 {
 #if defined(__s390x__) || defined(__s390__) || defined(__CRIS__)
-    return syscall(__NR_clone, NULL, flags);
+    return syscall(SYS_clone, NULL, flags);
 #else
-    return syscall(__NR_clone, flags, NULL);
+    return syscall(SYS_clone, flags, NULL);
 #endif
 }
 

src/nxt_isolation.c

@@ -1003,7 +1003,7 @@ fail:
 nxt_inline int
 nxt_pivot_root(const char *new_root, const char *old_root)
 {
-    return syscall(__NR_pivot_root, new_root, old_root);
+    return syscall(SYS_pivot_root, new_root, old_root);
 }
 
 

src/nxt_process.h

@@ -19,7 +19,7 @@
  * fork(2) calls.  As we use clone(2) for container, it returns the wrong pid.
  */
 #define nxt_getpid()                                                          \
-    syscall(__NR_getpid)
+    syscall(SYS_getpid)
 #else
 #define nxt_getpid()                                                          \
     getpid()