include: Include <unistd.h> in pidfd-utils.h for syscall()

In Glibc, <sys/syscall.h> only contains SYS_* macros and the syscall()
function is in <unistd.h>.  So include it.

Signed-off-by: Xi Ruoyao <xry111@xry111.site>

diff --git a/include/pidfd-utils.h b/include/pidfd-utils.h
index ff0bc4c792fc5e07bcecd4244142c0529eed52f0..0ee55f3bac08c7df08ac63fb0cf35e0822f18335 100644 (file)
--- a/include/pidfd-utils.h
+++ b/include/pidfd-utils.h
@@ -7,6 +7,7 @@
 
 #ifdef HAVE_SYS_SYSCALL_H
 # include <sys/syscall.h>
+# include <unistd.h>
 
 /*
  * If the kernel headers are too old to provide the syscall numbers, let's