posix: Fix posix_spawn implict check style

This patch fixes the implicit check style add in 2a69f85 for the
general convention one.

Checked on x86_64.

	* sysdeps/unix/sysv/linux/spawni.c (__spawnix): Fix implict checks
	style.

ChangeLog

@@ -1,3 +1,8 @@
+2016-03-21  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
+
+	* sysdeps/unix/sysv/linux/spawni.c (__spawnix): Fix implict checks
+	style.
+
 2016-03-21  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* sysdeps/unix/sysv/linux/x86_64/cancellation.S

sysdeps/unix/sysv/linux/spawni.c

@@ -381,7 +381,7 @@ __spawnix (pid_t * pid, const char *file,
 
   close_not_cancel (args.pipe[0]);
 
-  if (!ec && pid)
+  if ((ec == 0) && (pid != NULL))
     *pid = new_pid;
 
   __sigprocmask (SIG_SETMASK, &args.oldmask, 0);