osdep: Move default qemu_hw_version() value to a macro

The macro will be used by code that will stop calling
qemu_hw_version() at runtime and just need a constant value.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

include/qemu/osdep.h

@@ -327,6 +327,15 @@ static inline void qemu_timersub(const struct timeval *val1,
 
 void qemu_set_cloexec(int fd);
 
+/* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
+ * instead of QEMU_VERSION, so setting hw_version on MachineClass
+ * is no longer mandatory.
+ *
+ * Do NOT change this string, or it will break compatibility on all
+ * machine classes that don't set hw_version.
+ */
+#define QEMU_HW_VERSION "2.5+"
+
 /* QEMU "hardware version" setting. Used to replace code that exposed
  * QEMU_VERSION to guests in the past and need to keep compatibility.
  * Do not use qemu_hw_version() in new code.

util/osdep.c

@@ -44,14 +44,7 @@ extern int madvise(caddr_t, size_t, int);
 
 static bool fips_enabled = false;
 
-/* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
- * instead of QEMU_VERSION, so setting hw_version on MachineClass
- * is no longer mandatory.
- *
- * Do NOT change this string, or it will break compatibility on all
- * machine classes that don't set hw_version.
- */
-static const char *hw_version = "2.5+";
+static const char *hw_version = QEMU_HW_VERSION;
 
 int socket_set_cork(int fd, int v)
 {