hostmem: no need to check for host_memory_backend_mr_inited() in alloc()

memfd_backend_memory_alloc/file_backend_memory_alloc both needlessly
are are calling host_memory_backend_mr_inited() which creates an
illusion that alloc could be called multiple times but it isn't, it's
called once from UserCreatable complete().

Suggested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
index 639c8d4..6630021 100644
--- a/backends/hostmem-file.c
+++ b/backends/hostmem-file.c
@@ -42,6 +42,9 @@
 file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
 {
     HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);
+#ifdef CONFIG_POSIX
+    gchar *path;
+#endif
 
     if (!backend->size) {
         error_setg(errp, "can't create backend with size 0");
@@ -54,18 +57,15 @@
 #ifndef CONFIG_POSIX
     error_setg(errp, "-mem-path not supported on this host");
 #else
-    if (!host_memory_backend_mr_inited(backend)) {
-        gchar *path;
-        backend->force_prealloc = mem_prealloc;
-        path = object_get_canonical_path(OBJECT(backend));
-        memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
-                                 path,
-                                 backend->size, fb->align,
-                                 (backend->share ? RAM_SHARED : 0) |
-                                 (fb->is_pmem ? RAM_PMEM : 0),
-                                 fb->mem_path, errp);
-        g_free(path);
-    }
+    backend->force_prealloc = mem_prealloc;
+    path = object_get_canonical_path(OBJECT(backend));
+    memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
+                                     path,
+                                     backend->size, fb->align,
+                                     (backend->share ? RAM_SHARED : 0) |
+                                     (fb->is_pmem ? RAM_PMEM : 0),
+                                     fb->mem_path, errp);
+    g_free(path);
 #endif
 }
 
diff --git a/backends/hostmem-memfd.c b/backends/hostmem-memfd.c
index 1c3579e..2eb9c82 100644
--- a/backends/hostmem-memfd.c
+++ b/backends/hostmem-memfd.c
@@ -44,10 +44,6 @@
         return;
     }
 
-    if (host_memory_backend_mr_inited(backend)) {
-        return;
-    }
-
     backend->force_prealloc = mem_prealloc;
     fd = qemu_memfd_create(TYPE_MEMORY_BACKEND_MEMFD, backend->size,
                            m->hugetlb, m->hugetlbsize, m->seal ?