kconfig: add unexpected data itself to warning

If the .config parser runs into unexpected data it emits warnings like:
    .config:6911:warning: unexpected data

Add the unexpected data itself to this warning. That makes it easier to
discover what is actually going wrong:
     .config:6911:warning: unexpected data: CONFOG_CHARGER_TPS65217=m
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NMichal Marek <mmarek@suse.com>

scripts/kconfig/confdata.c

@@ -375,7 +375,9 @@ int conf_read_simple(const char *name, int def)
 				continue;
 		} else {
 			if (line[0] != '\r' && line[0] != '\n')
-				conf_warning("unexpected data");
+				conf_warning("unexpected data: %.*s",
+					     (int)strcspn(line, "\r\n"), line);
+
 			continue;
 		}
 setsym: