linux_compat: move vzalloc() to header file as an inline function

The vzalloc(size) is equivalent to kzalloc(size, 0).  Move it to
include/linux/compat.h as an inline function in order to avoid the
function call overhead.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/include/linux/compat.h b/include/linux/compat.h
index da1420f..a3d136b 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -40,6 +40,10 @@
 void *kzalloc(size_t size, int flags);
 #define vmalloc(size)	kmalloc(size, 0)
 #define __vmalloc(size, flags, pgsz)	kmalloc(size, flags)
+static inline void *vzalloc(unsigned long size)
+{
+	return kzalloc(size, 0);
+}
 #define kfree(ptr)	free(ptr)
 #define vfree(ptr)	free(ptr)
 
@@ -189,8 +193,6 @@
 unsigned long copy_from_user(void *dest, const void *src,
 			     unsigned long count);
 
-void *vzalloc(unsigned long size);
-
 typedef unused_t spinlock_t;
 typedef int	wait_queue_head_t;
 
diff --git a/lib/linux_compat.c b/lib/linux_compat.c
index a3d4675..8c7a7b5 100644
--- a/lib/linux_compat.c
+++ b/lib/linux_compat.c
@@ -26,11 +26,6 @@
 	return ptr;
 }
 
-void *vzalloc(unsigned long size)
-{
-	return kzalloc(size, 0);
-}
-
 struct kmem_cache *get_mem(int element_sz)
 {
 	struct kmem_cache *ret;