[cmdline] Allow ";" as an unconditional command separator

It is currently possible to construct a sequence of commands to be
executed regardless of success or failure using "|| &&" as the command
separator.  (The "||" captures the failure case, the blank command
converts it to a success case.)

Allow ";" to be used as a more visually appealing (and
space-efficient) alternative.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/exec.c

 	return ( rc != 0 );
 }
 
+/**
+ * Process next command regardless of status from previous command
+ *
+ * @v rc		Status of previous command
+ * @ret process		Process next command
+ */
+static int process_always ( int rc __unused ) {
+	return 1;
+}
+
 /**
  * Find command terminator
  *
 			/* Short-circuit logical AND */
 			*process_next = process_on_success;
 			return i;
+		} else if ( strcmp ( tokens[i], ";" ) == 0 ) {
+			/* Process next command unconditionally */
+			*process_next = process_always;
+			return i;
 		}
 	}