memblock tests: include export.h in linkage.h as kernel dose

In kernel code, linkage.h includes export.h. Let's sync with kernel.

This is a preparation for move init.h in common include directory.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Mike Rapoport <rppt@kernel.org>
Link: https://lore.kernel.org/r/20240712035138.24674-2-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

Author: RichardWeiYang

tools/include/linux/linkage.h

@@ -1,4 +1,6 @@
 #ifndef _TOOLS_INCLUDE_LINUX_LINKAGE_H
 #define _TOOLS_INCLUDE_LINUX_LINKAGE_H
 
+#include <linux/export.h>
+
 #endif /* _TOOLS_INCLUDE_LINUX_LINKAGE_H */

tools/testing/memblock/linux/init.h

@@ -3,7 +3,6 @@
 #define _LINUX_INIT_H
 
 #include <linux/compiler.h>
-#include <asm/export.h>
 
 #define __section(section)              __attribute__((__section__(section)))