tools: libxl: unbreak build after ec41430ef6a7

tools: libxl: unbreak build after ec41430ef6a7

libxl_create.c: In function ‘libxl__domain_build_info_setdefault’:
libxl_create.c:109: error: ‘info’ undeclared (first use in this function)
libxl_create.c:109: error: (Each undeclared identifier is reported only once
libxl_create.c:109: error: for each function it appears in.)
cc1: warnings being treated as errors
libxl_create.c:108: error: suggest explicit braces to avoid ambiguous ‘else’
libxl_create.c: At top level:
libxl_create.c:141: error: expected identifier or ‘(’ before ‘if’
...

Fix is to insert the missing opening brace and s/info/b_info/ in one spot.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>