fs: Export anon_inode_getfile_secure() for use by KVM

Export anon_inode_getfile_secure() so that it can be used by KVM to create
and manage file-based guest memory without need a fullblow filesystem.
The "standard" anon_inode_getfd() doesn't work for KVM's use case as KVM
needs a unique inode for each file, e.g. to be able to independently
manage the size and lifecycle of a given file.

Note, KVM doesn't need a "secure" version, just unique inodes, i.e. ignore
the name.

Signed-off-by: Sean Christopherson <[email protected]>
Reviewed-by: Paolo Bonzini <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

fs/anon_inodes.c

@@ -176,6 +176,7 @@ struct file *anon_inode_getfile_secure(const char *name,
 	return __anon_inode_getfile(name, fops, priv, flags,
 				    context_inode, true);
 }
+EXPORT_SYMBOL_GPL(anon_inode_getfile_secure);
 
 static int __anon_inode_getfd(const char *name,
 			      const struct file_operations *fops,