api.c: cg_build_path_locked() - work around snprintf() warnings

api.c: cg_build_path_locked() - work around snprintf() warnings

Recent gcc are unhappy when sizeof(dest) <= sizeof(src) with
snprintf()'s. We could need too many strncpy()'s and strcat()'s for
constructing file path, so let's workaround it by allocating long
enough space for keeping snprintf() happy and then use the temporarily
allocated array and use it as src for strncpy() with limit of
FILENAME_MAX.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>