libxl: don't shadow global "socket" in psr code

libxl: don't shadow global "socket" in psr code

SLES11 and OpenSUSE 11.4 complain:

[ 1227s] libxl_psr.c: In function 'libxl_psr_cat_get_l3_info':
[ 1227s] libxl_psr.c:342: error: declaration of 'socket' shadows a > global declaration

Change "socket" to "socketid" to fix the problem.

Reported-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Cc: Chao Peng <chao.p.peng@linux.intel.com>
Tested-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>