xen: use correct type for HYPERVISOR_memory_op()

HYPERVISOR_memory_op() is defined to return an "int" value. This is
wrong, as the Xen hypervisor will return "long".

The sub-function XENMEM_maximum_reservation returns the maximum
number of pages for the current domain. An int will overflow for a
domain configured with 8TB of memory or more.

Correct this by using the correct type.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

arch/x86/include/asm/xen/hypercall.h

@@ -336,10 +336,10 @@ HYPERVISOR_update_descriptor(u64 ma, u64 desc)
 	return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
 }
 
-static inline int
+static inline long
 HYPERVISOR_memory_op(unsigned int cmd, void *arg)
 {
-	return _hypercall2(int, memory_op, cmd, arg);
+	return _hypercall2(long, memory_op, cmd, arg);
 }
 
 static inline int

arch/x86/xen/setup.c

@@ -548,7 +548,7 @@ static unsigned long __init xen_get_max_pages(void)
 {
 	unsigned long max_pages, limit;
 	domid_t domid = DOMID_SELF;
-	int ret;
+	long ret;
 
 	limit = xen_get_pages_limit();
 	max_pages = limit;