libsepol: use the number of elements in calloc first argument

When allocating an array with calloc(), the first argument usually is
the number of items and the second one the size of an item. Doing so
silences a warning reported by clang's static analyzer:

    kernel_to_cil.c:2050:14: warning: Call to 'calloc' has an allocation
    size of 0 bytes.
            cond_data = calloc(sizeof(struct cond_data), num);
                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>

libsepol/src/kernel_to_cil.c

@@ -2043,7 +2043,7 @@ static int write_cond_nodes_to_cil(FILE *out, struct policydb *pdb)
 		num++;
 	}
 
-	cond_data = calloc(sizeof(struct cond_data), num);
+	cond_data = calloc(num, sizeof(struct cond_data));
 	if (!cond_data) {
 		rc = -1;
 		goto exit;