cxl: Fix a memory leak in an error handling path

A bitmap_zalloc() must be balanced by a corresponding bitmap_free() in the
error handling path of afu_allocate_irqs().

Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/ce5869418f5838187946eb6b11a52715a93ece3d.1657566849.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>