add some more comments

libbb/syscalls.c

@@ -50,12 +50,12 @@ int pivot_root(const char * new_root,const char * put_old)
 	return -1;
 #else
 	return(syscall(__NR_pivot_root, new_root, put_old));
-#endif
+#endif /* __NR_pivot_root */
 }
 
 
-
-/* These syscalls are not included in ancient glibc versions */
+/* These syscalls are not included in ancient glibc versions,
+   so we have to define them ourselves, whee ! */
 #if ((__GLIBC__ <= 2) && (__GLIBC_MINOR__ < 1))
 
 int bdflush(int func, int data)
@@ -69,7 +69,7 @@ int klogctl(int type, char *b, int len)
 {
 	return(syscall(__NR_klogctl, type, b, len));
 }
-#endif
+#endif /* __alpha__ */
 
 
 int umount2(const char * special_file, int flags)
@@ -88,11 +88,10 @@ int umount2(const char * special_file, int flags)
 	return -1;
 #else
 	return(syscall(__NR_umount2, special_file, flags));
-#endif
+#endif /* __NR_pivot_root */
 }
 
-
-#endif
+#endif /* old glibc check */
 
 
 /* END CODE */