obmc-console: Fix readability-isolate-declaration

For example:

```
/usr/bin/clang-tidy -checks=-*, readability-isolate-declaration -export-fixes /tmp/tmpoo7fbs72/tmpo8xiwfxs.yaml -p=build /mnt/host/andrew/home/andrew/src/openbmc/obmc-console/test/test-client-escape.c
/mnt/host/andrew/home/andrew/src/openbmc/obmc-console/build/../config.c:61:2: error: multiple declarations in a single statement reduces readability [readability-isolate-declaration,-warnings-as-errors]
        char *name, *value;
        ^~~~~~~~~~~~~~~~~~~
/mnt/host/andrew/home/andrew/src/openbmc/obmc-console/build/../config.c:62:2: error: multiple declarations in a single statement reduces readability [readability-isolate-declaration,-warnings-as-errors]
        char *p, *line;
        ^~~~~~~~~~~~~~~
/mnt/host/andrew/home/andrew/src/openbmc/obmc-console/build/../config.c:110:2: error: multiple declarations in a single statement reduces readability [readability-isolate-declaration,-warnings-as-errors]
        size_t size, len;
        ^~~~~~~~~~~~~~~~~
/mnt/host/andrew/home/andrew/src/openbmc/obmc-console/build/../config.c:170:2: error: multiple declarations in a single statement reduces readability [readability-isolate-declaration,-warnings-as-errors]
        struct config_item *item, *next;
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/mnt/host/andrew/home/andrew/src/openbmc/obmc-console/build/../console-client.c:263:2: error: multiple declarations in a single statement reduces readability [readability-isolate-declaration,-warnings-as-errors]
        struct console_client _client, *client;
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
6 warnings generated.
```

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: Ia7829b1672ea2dfb3fa020c7c48bd8266e6a1769
diff --git a/test/test-ringbuffer-read-commit.c b/test/test-ringbuffer-read-commit.c
index 0dba0d7..9173b9f 100644
--- a/test/test-ringbuffer-read-commit.c
+++ b/test/test-ringbuffer-read-commit.c
@@ -8,7 +8,8 @@
 
 void test_read_commit(void)
 {
-	uint8_t *out_buf, in_buf[] = {
+	uint8_t *out_buf;
+	uint8_t in_buf[] = {
 		'a',
 		'b',
 		'c',