Fix typecast error for x86_64
Fix typecast error for x86_64

Signed-off-by:  Steven Munroe  <sjmunroe@us.ibm.com>

        * src/sasatom_x86_64.h (__arch_fetch_and_add_ptr): Fix typecast error.
	(__arch_fetch_and_add): Likewise.

RajalakshmiS/sphde,sphde/sphde,sphde/sphde,frediz/sphde,RajalakshmiS/sphde,sphde/sphde,frediz/sphde,RajalakshmiS/sphde,frediz/sphde