tools/libxc: Fix build of 32bit toolstacks on CentOS 5.x following XSA-125

gcc 4.1 of CentOS 5.x era does not like the typecheck in min() between
uint64_t and unsigned long.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>

tools/libxc/xc_domain.c

@@ -1641,12 +1641,9 @@ failed:
     return -1;
 }
 
-#ifndef min
-#define min(X, Y) ({                             \
-            const typeof (X) _x = (X);           \
-            const typeof (Y) _y = (Y);           \
-            (void) (&_x == &_y);                 \
-            (_x < _y) ? _x : _y; })
+#ifndef min_t
+#define min_t(type,x,y) \
+    ({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
 #endif
 int xc_domain_memory_mapping(
     xc_interface *xch,
@@ -1669,7 +1666,7 @@ int xc_domain_memory_mapping(
     max_batch_sz = nr_mfns;
     do
     {
-        nr = min(nr_mfns - done, max_batch_sz);
+        nr = min_t(unsigned long, nr_mfns - done, max_batch_sz);
         domctl.u.memory_mapping.nr_mfns = nr;
         domctl.u.memory_mapping.first_gfn = first_gfn + done;
         domctl.u.memory_mapping.first_mfn = first_mfn + done;
@@ -1705,7 +1702,7 @@ int xc_domain_memory_mapping(
 
     return ret;
 }
-#undef min
+#undef min_t
 int xc_domain_ioport_mapping(
     xc_interface *xch,
     uint32_t domid,