make: clarify an error string

[Michael W. Bombardieri]

Hi,

In make(1), do_run_command() has a sanity check for a null command string.
The error message passes the null string to printf(). Is this any better?

- Michael
 

Index: engine.c
===================================================================
RCS file: /cvs/src/usr.bin/make/engine.c,v
retrieving revision 1.53
diff -u -p -u -r1.53 engine.c
--- engine.c    9 Jul 2017 15:28:00 -0000       1.53
+++ engine.c    24 Jul 2017 06:58:31 -0000
@@ -752,7 +752,7 @@ do_run_command(Job *job)
        /* How can we execute a null command ? we warn the user that the
         * command expanded to nothing (is this the right thing to do?).  */
        if (*cmd == '\0') {
-               Error("%s expands to empty string", cmd);
+               Error("command expands to empty string");
                return false;
        }