mm/util.c must #include <linux/sched.h>

mm/util.c: In function 'arch_pick_mmap_layout':
  mm/util.c:144: error: dereferencing pointer to incomplete type
  mm/util.c:145: error: 'arch_get_unmapped_area' undeclared (first use in this function)
  mm/util.c:145: error: (Each undeclared identifier is reported only once
  mm/util.c:145: error: for each function it appears in.)
  mm/util.c:146: error: 'arch_unmap_area' undeclared (first use in this function)

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/util.c b/mm/util.c
index 0efd830..d8d0221 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -3,6 +3,7 @@
 #include <linux/string.h>
 #include <linux/module.h>
 #include <linux/err.h>
+#include <linux/sched.h>
 #include <asm/uaccess.h>
 
 /**