dc(1): always use bn_checkp()

[kshe]

Hi,

This is the only instance where a manual check is made instead of
calling bn_checkp().

Index: mem.c
===================================================================
RCS file: /cvs/src/usr.bin/dc/mem.c,v
retrieving revision 1.7
diff -u -p -r1.7 mem.c
--- mem.c       16 Feb 2015 20:53:34 -0000      1.7
+++ mem.c       7 Dec 2017 04:13:06 -0000
@@ -32,8 +32,7 @@ new_number(void)
        n = bmalloc(sizeof(*n));
        n->scale = 0;
        n->number = BN_new();
-       if (n->number == NULL)
-               err(1, NULL);
+       bn_checkp(n->number);
        return n;
 }
 

Regards,

kshe