Add missing include to fix checks.

Author: BsAtHome

src/hal/drivers/mesa-hostmot2/eshellf.c

@@ -20,12 +20,14 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <stdarg.h>
 #include <errno.h>
 #include <sys/wait.h>
 
 #include <rtapi.h>
 
+
 int shell(char *command)
 {
 	char *const argv[] = {"sh", "-c", command, NULL};