Replace qemu_real_host_page variables with inlined functions

Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.

This avoids the need for a constructor initialization too.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/cpu.c b/cpu.c
index d34c343..ab2c7c8 100644
--- a/cpu.c
+++ b/cpu.c
@@ -481,7 +481,7 @@
     /* NOTE: we can always suppose that qemu_host_page_size >=
        TARGET_PAGE_SIZE */
     if (qemu_host_page_size == 0) {
-        qemu_host_page_size = qemu_real_host_page_size;
+        qemu_host_page_size = qemu_real_host_page_size();
     }
     if (qemu_host_page_size < TARGET_PAGE_SIZE) {
         qemu_host_page_size = TARGET_PAGE_SIZE;