memory: fix label syntax

memory: fix label syntax

When compiling this file with gcc, the compiler happily accepts the
sequence of a label followed by an attribute. However, this sequence does
not follow the gcc documentation. Hence, other compilers might stumble
upon this statement.

To be able to compile Xen with goto-cc (the compiler of the CPROVER tool
suite), the missing semicolon is added in this commit.

Reported-by: Elizabeth Polgreen <polgreen@amazon.de>
Signed-off-by: Norbert Manthey <nmanthey@amazon.de>
Reviewed-by: Jan Beulich <jbeulich@suse.com>